Added in nullable annotation for responses.

88 files changed, 660 insertions, 306 deletions

diff --git a/SmartDeviceLink/SDLAddCommandResponse.h b/SmartDeviceLink/SDLAddCommandResponse.h
index ee037f281..554f59d82 100644
--- a/SmartDeviceLink/SDLAddCommandResponse.h
+++ b/SmartDeviceLink/SDLAddCommandResponse.h
@@ -9,6 +9,11 @@
  *
  * Since <b>SmartDeviceLink 1.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAddCommandResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAddCommandResponse.m b/SmartDeviceLink/SDLAddCommandResponse.m
index f02a460a1..d5504c4c8 100644
--- a/SmartDeviceLink/SDLAddCommandResponse.m
+++ b/SmartDeviceLink/SDLAddCommandResponse.m
@@ -4,6 +4,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAddCommandResponse
 
 - (instancetype)init {
@@ -13,3 +15,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAddSubMenuResponse.h b/SmartDeviceLink/SDLAddSubMenuResponse.h
index b3124433b..17305aace 100644
--- a/SmartDeviceLink/SDLAddSubMenuResponse.h
+++ b/SmartDeviceLink/SDLAddSubMenuResponse.h
@@ -7,6 +7,11 @@
  * SDLAddSubMenuResponse is sent, when SDLAddSubMenu has been called
  * Since <b>SmartDeviceLink 1.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAddSubMenuResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAddSubMenuResponse.m b/SmartDeviceLink/SDLAddSubMenuResponse.m
index 328a38401..db483cf3a 100644
--- a/SmartDeviceLink/SDLAddSubMenuResponse.m
+++ b/SmartDeviceLink/SDLAddSubMenuResponse.m
@@ -4,6 +4,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAddSubMenuResponse
 
 - (instancetype)init {
@@ -13,3 +15,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlertManeuverResponse.h b/SmartDeviceLink/SDLAlertManeuverResponse.h
index 41dcaaa5e..d541cde0e 100644
--- a/SmartDeviceLink/SDLAlertManeuverResponse.h
+++ b/SmartDeviceLink/SDLAlertManeuverResponse.h
@@ -7,6 +7,11 @@
 /** SDLAlertManeuverResponse is sent, when SDLAlertManeuver has been called.
  * @since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAlertManeuverResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlertManeuverResponse.m b/SmartDeviceLink/SDLAlertManeuverResponse.m
index 60581be85..b66d13afe 100644
--- a/SmartDeviceLink/SDLAlertManeuverResponse.m
+++ b/SmartDeviceLink/SDLAlertManeuverResponse.m
@@ -5,6 +5,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAlertManeuverResponse
 
 - (instancetype)init {
@@ -14,3 +16,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlertResponse.h b/SmartDeviceLink/SDLAlertResponse.h
index beca991f1..f3269c709 100644
--- a/SmartDeviceLink/SDLAlertResponse.h
+++ b/SmartDeviceLink/SDLAlertResponse.h
@@ -8,8 +8,13 @@
  * Sent after SDLAlert has been sent
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAlertResponse : SDLRPCResponse
 
-@property (strong) NSNumber<SDLInt> *tryAgainTime;
+@property (nullable, strong) NSNumber<SDLInt> *tryAgainTime;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlertResponse.m b/SmartDeviceLink/SDLAlertResponse.m
index e2a3af5e1..e608b807c 100644
--- a/SmartDeviceLink/SDLAlertResponse.m
+++ b/SmartDeviceLink/SDLAlertResponse.m
@@ -13,7 +13,7 @@
     return self;
 }
 
-- (void)setTryAgainTime:(NSNumber<SDLInt> *)tryAgainTime {
+- (void)setTryAgainTime:(nullable NSNumber<SDLInt> *)tryAgainTime {
     if (tryAgainTime != nil) {
         [parameters setObject:tryAgainTime forKey:SDLNameTryAgainTime];
     } else {
@@ -21,7 +21,7 @@
     }
 }
 
-- (NSNumber<SDLInt> *)tryAgainTime {
+- (nullable NSNumber<SDLInt> *)tryAgainTime {
     return [parameters objectForKey:SDLNameTryAgainTime];
 }
 
diff --git a/SmartDeviceLink/SDLChangeRegistrationResponse.h b/SmartDeviceLink/SDLChangeRegistrationResponse.h
index 20017d066..89c469fd9 100644
--- a/SmartDeviceLink/SDLChangeRegistrationResponse.h
+++ b/SmartDeviceLink/SDLChangeRegistrationResponse.h
@@ -9,6 +9,11 @@
  *
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLChangeRegistrationResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLChangeRegistrationResponse.m b/SmartDeviceLink/SDLChangeRegistrationResponse.m
index a4cab1c9b..ab03f7e8b 100644
--- a/SmartDeviceLink/SDLChangeRegistrationResponse.m
+++ b/SmartDeviceLink/SDLChangeRegistrationResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLChangeRegistrationResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.h b/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.h
index 0573dcc2f..0f9cd4346 100644
--- a/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.h
+++ b/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.h
@@ -10,6 +10,11 @@
  *
  * Since <b>SmartDeviceLink 1.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLCreateInteractionChoiceSetResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.m b/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.m
index 11b055e82..80f623f08 100644
--- a/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.m
+++ b/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLCreateInteractionChoiceSetResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteCommandResponse.h b/SmartDeviceLink/SDLDeleteCommandResponse.h
index 4c07a3c2f..95df39a6f 100644
--- a/SmartDeviceLink/SDLDeleteCommandResponse.h
+++ b/SmartDeviceLink/SDLDeleteCommandResponse.h
@@ -9,6 +9,11 @@
  *
  * Since <b>SmartDeviceLink 1.0</b><br>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteCommandResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteCommandResponse.m b/SmartDeviceLink/SDLDeleteCommandResponse.m
index 7f97574cb..b4ee8167d 100644
--- a/SmartDeviceLink/SDLDeleteCommandResponse.m
+++ b/SmartDeviceLink/SDLDeleteCommandResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteCommandResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteFileResponse.h b/SmartDeviceLink/SDLDeleteFileResponse.h
index dc2a91f4d..8e7cb2107 100644
--- a/SmartDeviceLink/SDLDeleteFileResponse.h
+++ b/SmartDeviceLink/SDLDeleteFileResponse.h
@@ -9,8 +9,13 @@
  *
  * Since <b>SmartDeviceLink 2.0</b><br>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteFileResponse : SDLRPCResponse
 
 @property (strong) NSNumber<SDLInt> *spaceAvailable;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteFileResponse.m b/SmartDeviceLink/SDLDeleteFileResponse.m
index f2a77b19e..1ae2c41f3 100644
--- a/SmartDeviceLink/SDLDeleteFileResponse.m
+++ b/SmartDeviceLink/SDLDeleteFileResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteFileResponse
 
 - (instancetype)init {
@@ -27,3 +29,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.h b/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.h
index c67aef1d1..ad0dc0fc7 100644
--- a/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.h
+++ b/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.h
@@ -9,6 +9,11 @@
  *
  * Since <b>SmartDeviceLink 1.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteInteractionChoiceSetResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.m b/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.m
index bcca0be95..37b7c7940 100644
--- a/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.m
+++ b/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteInteractionChoiceSetResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteSubMenuResponse.h b/SmartDeviceLink/SDLDeleteSubMenuResponse.h
index 5842a54be..e50781e85 100644
--- a/SmartDeviceLink/SDLDeleteSubMenuResponse.h
+++ b/SmartDeviceLink/SDLDeleteSubMenuResponse.h
@@ -9,6 +9,11 @@
  *
  * Since <b>SmartDeviceLink 1.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteSubMenuResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteSubMenuResponse.m b/SmartDeviceLink/SDLDeleteSubMenuResponse.m
index a9755f8a2..ec77c8944 100644
--- a/SmartDeviceLink/SDLDeleteSubMenuResponse.m
+++ b/SmartDeviceLink/SDLDeleteSubMenuResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteSubMenuResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDiagnosticMessageResponse.h b/SmartDeviceLink/SDLDiagnosticMessageResponse.h
index 7021a91ed..3396dceb1 100644
--- a/SmartDeviceLink/SDLDiagnosticMessageResponse.h
+++ b/SmartDeviceLink/SDLDiagnosticMessageResponse.h
@@ -7,8 +7,13 @@
 /** SDLDiagnosticMessageResponse is sent, when SDLDiagnosticMessage has been called.
  * Since<b>SmartDeviceLink 3.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDiagnosticMessageResponse : SDLRPCResponse
 
 @property (strong) NSMutableArray<NSNumber<SDLInt> *> *messageDataResult;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDiagnosticMessageResponse.m b/SmartDeviceLink/SDLDiagnosticMessageResponse.m
index 46c077f7a..3c110128d 100644
--- a/SmartDeviceLink/SDLDiagnosticMessageResponse.m
+++ b/SmartDeviceLink/SDLDiagnosticMessageResponse.m
@@ -5,6 +5,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDiagnosticMessageResponse
 
 - (instancetype)init {
@@ -26,3 +28,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDialNumberResponse.h b/SmartDeviceLink/SDLDialNumberResponse.h
index 1270751ac..7f8dfaa14 100644
--- a/SmartDeviceLink/SDLDialNumberResponse.h
+++ b/SmartDeviceLink/SDLDialNumberResponse.h
@@ -9,6 +9,11 @@
  
  @since SDL 4.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDialNumberResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDialNumberResponse.m b/SmartDeviceLink/SDLDialNumberResponse.m
index 3d16f2621..9a8a1c5f1 100644
--- a/SmartDeviceLink/SDLDialNumberResponse.m
+++ b/SmartDeviceLink/SDLDialNumberResponse.m
@@ -6,6 +6,7 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLDialNumberResponse
 
@@ -16,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEncodedSyncPDataResponse.h b/SmartDeviceLink/SDLEncodedSyncPDataResponse.h
index ff1dec1ac..f8a4daf20 100644
--- a/SmartDeviceLink/SDLEncodedSyncPDataResponse.h
+++ b/SmartDeviceLink/SDLEncodedSyncPDataResponse.h
@@ -4,6 +4,10 @@
 
 #import "SDLRPCResponse.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLEncodedSyncPDataResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEncodedSyncPDataResponse.m b/SmartDeviceLink/SDLEncodedSyncPDataResponse.m
index d469e1bfa..ecde6b6e4 100644
--- a/SmartDeviceLink/SDLEncodedSyncPDataResponse.m
+++ b/SmartDeviceLink/SDLEncodedSyncPDataResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLEncodedSyncPDataResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEndAudioPassThruResponse.h b/SmartDeviceLink/SDLEndAudioPassThruResponse.h
index 1e976a6f8..bda7b4f89 100644
--- a/SmartDeviceLink/SDLEndAudioPassThruResponse.h
+++ b/SmartDeviceLink/SDLEndAudioPassThruResponse.h
@@ -9,6 +9,11 @@
  *
  * Since <b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLEndAudioPassThruResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEndAudioPassThruResponse.m b/SmartDeviceLink/SDLEndAudioPassThruResponse.m
index 9cad307ec..e9218d3d6 100644
--- a/SmartDeviceLink/SDLEndAudioPassThruResponse.m
+++ b/SmartDeviceLink/SDLEndAudioPassThruResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLEndAudioPassThruResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGenericResponse.h b/SmartDeviceLink/SDLGenericResponse.h
index 61e1f2c8d..74f1fa495 100644
--- a/SmartDeviceLink/SDLGenericResponse.h
+++ b/SmartDeviceLink/SDLGenericResponse.h
@@ -9,6 +9,11 @@
  * retrieved. Only used in case of an error. Currently, only resultCode
  * INVALID_DATA is used.
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLGenericResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGenericResponse.m b/SmartDeviceLink/SDLGenericResponse.m
index a6a0a8ee9..34368d397 100644
--- a/SmartDeviceLink/SDLGenericResponse.m
+++ b/SmartDeviceLink/SDLGenericResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLGenericResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetDTCsResponse.h b/SmartDeviceLink/SDLGetDTCsResponse.h
index a07d9ced6..f9511ea4e 100644
--- a/SmartDeviceLink/SDLGetDTCsResponse.h
+++ b/SmartDeviceLink/SDLGetDTCsResponse.h
@@ -9,9 +9,14 @@
  *
  * Since <b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLGetDTCsResponse : SDLRPCResponse
 
 @property (strong) NSNumber<SDLInt> *ecuHeader;
 @property (strong) NSMutableArray<NSString *> *dtc;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetDTCsResponse.m b/SmartDeviceLink/SDLGetDTCsResponse.m
index 0f77b48ec..6a9edd79c 100644
--- a/SmartDeviceLink/SDLGetDTCsResponse.m
+++ b/SmartDeviceLink/SDLGetDTCsResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLGetDTCsResponse
 
 - (instancetype)init {
@@ -39,3 +41,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetVehicleDataResponse.h b/SmartDeviceLink/SDLGetVehicleDataResponse.h
index d8a4c64ca..c851e96f2 100644
--- a/SmartDeviceLink/SDLGetVehicleDataResponse.h
+++ b/SmartDeviceLink/SDLGetVehicleDataResponse.h
@@ -27,111 +27,116 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLGetVehicleDataResponse : SDLRPCResponse
 
 /**
  * @abstract A SDLGPSData* value. See GPSData.
  */
-@property (strong) SDLGPSData *gps;
+@property (nullable, strong) SDLGPSData *gps;
 
 /**
  * @abstract The vehicle speed in kilometers per hour.
  */
-@property (strong) NSNumber<SDLFloat> *speed;
+@property (nullable, strong) NSNumber<SDLFloat> *speed;
 
 /**
  * @abstract The number of revolutions per minute of the engine.
  */
-@property (strong) NSNumber<SDLInt> *rpm;
+@property (nullable, strong) NSNumber<SDLInt> *rpm;
 
 /**
  * @abstract The fuel level in the tank (percentage)
  */
-@property (strong) NSNumber<SDLFloat> *fuelLevel;
+@property (nullable, strong) NSNumber<SDLFloat> *fuelLevel;
 
 /**
  * @abstract A SDLComponentVolumeStatus* value. The fuel level state.
  */
-@property (strong) SDLComponentVolumeStatus fuelLevel_State;
+@property (nullable, strong) SDLComponentVolumeStatus fuelLevel_State;
 
 /**
  * @abstract The instantaneous fuel consumption in microlitres.
  */
-@property (strong) NSNumber<SDLFloat> *instantFuelConsumption;
+@property (nullable, strong) NSNumber<SDLFloat> *instantFuelConsumption;
 
 /**
  * @abstract The external temperature in degrees celsius.
  */
-@property (strong) NSNumber<SDLFloat> *externalTemperature;
+@property (nullable, strong) NSNumber<SDLFloat> *externalTemperature;
 
 /**
  * @abstract The Vehicle Identification Number
  */
-@property (strong) NSString *vin;
+@property (nullable, strong) NSString *vin;
 
 /**
  * @abstract See PRNDL.
  */
-@property (strong) SDLPRNDL prndl;
+@property (nullable, strong) SDLPRNDL prndl;
 
 /**
  * @abstract A SDLTireStatus* value. See TireStatus.
  */
-@property (strong) SDLTireStatus *tirePressure;
+@property (nullable, strong) SDLTireStatus *tirePressure;
 
 /**
  * @abstract Odometer reading in km.
  */
-@property (strong) NSNumber<SDLInt> *odometer;
+@property (nullable, strong) NSNumber<SDLInt> *odometer;
 
 /**
  * @abstract A SDLBeltStatus* value. The status of the seat belts.
  */
-@property (strong) SDLBeltStatus *beltStatus;
+@property (nullable, strong) SDLBeltStatus *beltStatus;
 
 /**
  * @abstract A SDLBodyInformation* value. The body information including power modes.
  */
-@property (strong) SDLBodyInformation *bodyInformation;
+@property (nullable, strong) SDLBodyInformation *bodyInformation;
 
 /**
  * @abstract A SDLDeviceStatus* value. The device status including signal and battery strength.
  */
-@property (strong) SDLDeviceStatus *deviceStatus;
+@property (nullable, strong) SDLDeviceStatus *deviceStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the brake pedal.
  */
-@property (strong) SDLVehicleDataEventStatus driverBraking;
+@property (nullable, strong) SDLVehicleDataEventStatus driverBraking;
 
 /**
  * @abstract A SDLWiperStatus* value. The status of the wipers.
  */
-@property (strong) SDLWiperStatus wiperStatus;
+@property (nullable, strong) SDLWiperStatus wiperStatus;
 
 /**
  * @abstract A SDLHeadLampStatus* value. Status of the head lamps.
  */
-@property (strong) SDLHeadLampStatus *headLampStatus;
+@property (nullable, strong) SDLHeadLampStatus *headLampStatus;
 
 /**
  * @abstract Torque value for engine (in Nm) on non-diesel variants.
  */
-@property (strong) NSNumber<SDLFloat> *engineTorque;
+@property (nullable, strong) NSNumber<SDLFloat> *engineTorque;
 
 /**
  * @abstract Accelerator pedal position (percentage depressed)
  */
-@property (strong) NSNumber<SDLFloat> *accPedalPosition;
+@property (nullable, strong) NSNumber<SDLFloat> *accPedalPosition;
 
 /**
  * @abstract Current angle of the steering wheel (in deg)
  */
-@property (strong) NSNumber<SDLFloat> *steeringWheelAngle;
-@property (strong) SDLECallInfo *eCallInfo;
-@property (strong) SDLAirbagStatus *airbagStatus;
-@property (strong) SDLEmergencyEvent *emergencyEvent;
-@property (strong) SDLClusterModeStatus *clusterModeStatus;
-@property (strong) SDLMyKey *myKey;
+@property (nullable, strong) NSNumber<SDLFloat> *steeringWheelAngle;
+@property (nullable, strong) SDLECallInfo *eCallInfo;
+@property (nullable, strong) SDLAirbagStatus *airbagStatus;
+@property (nullable, strong) SDLEmergencyEvent *emergencyEvent;
+@property (nullable, strong) SDLClusterModeStatus *clusterModeStatus;
+@property (nullable, strong) SDLMyKey *myKey;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetVehicleDataResponse.m b/SmartDeviceLink/SDLGetVehicleDataResponse.m
index ea798a430..fa04f98be 100644
--- a/SmartDeviceLink/SDLGetVehicleDataResponse.m
+++ b/SmartDeviceLink/SDLGetVehicleDataResponse.m
@@ -26,7 +26,7 @@
     return self;
 }
 
-- (void)setGps:(SDLGPSData *)gps {
+- (void)setGps:(nullable SDLGPSData *)gps {
     if (gps != nil) {
         [parameters setObject:gps forKey:SDLNameGPS];
     } else {
@@ -34,7 +34,7 @@
     }
 }
 
-- (SDLGPSData *)gps {
+- (nullable SDLGPSData *)gps {
     NSObject *obj = [parameters objectForKey:SDLNameGPS];
     if (obj == nil || [obj isKindOfClass:SDLGPSData.class]) {
         return (SDLGPSData *)obj;
@@ -43,7 +43,7 @@
     }
 }
 
-- (void)setSpeed:(NSNumber<SDLFloat> *)speed {
+- (void)setSpeed:(nullable NSNumber<SDLFloat> *)speed {
     if (speed != nil) {
         [parameters setObject:speed forKey:SDLNameSpeed];
     } else {
@@ -51,11 +51,11 @@
     }
 }
 
-- (NSNumber<SDLFloat> *)speed {
+- (nullable NSNumber<SDLFloat> *)speed {
     return [parameters objectForKey:SDLNameSpeed];
 }
 
-- (void)setRpm:(NSNumber<SDLInt> *)rpm {
+- (void)setRpm:(nullable NSNumber<SDLInt> *)rpm {
     if (rpm != nil) {
         [parameters setObject:rpm forKey:SDLNameRPM];
     } else {
@@ -63,11 +63,11 @@
     }
 }
 
-- (NSNumber<SDLInt> *)rpm {
+- (nullable NSNumber<SDLInt> *)rpm {
     return [parameters objectForKey:SDLNameRPM];
 }
 
-- (void)setFuelLevel:(NSNumber<SDLFloat> *)fuelLevel {
+- (void)setFuelLevel:(nullable NSNumber<SDLFloat> *)fuelLevel {
     if (fuelLevel != nil) {
         [parameters setObject:fuelLevel forKey:SDLNameFuelLevel];
     } else {
@@ -75,11 +75,11 @@
     }
 }
 
-- (NSNumber<SDLFloat> *)fuelLevel {
+- (nullable NSNumber<SDLFloat> *)fuelLevel {
     return [parameters objectForKey:SDLNameFuelLevel];
 }
 
-- (void)setFuelLevel_State:(SDLComponentVolumeStatus)fuelLevel_State {
+- (void)setFuelLevel_State:(nullable SDLComponentVolumeStatus)fuelLevel_State {
     if (fuelLevel_State != nil) {
         [parameters setObject:fuelLevel_State forKey:SDLNameFuelLevelState];
     } else {
@@ -87,12 +87,12 @@
     }
 }
 
-- (SDLComponentVolumeStatus)fuelLevel_State {
+- (nullable SDLComponentVolumeStatus)fuelLevel_State {
     NSObject *obj = [parameters objectForKey:SDLNameFuelLevelState];
     return (SDLComponentVolumeStatus)obj;
 }
 
-- (void)setInstantFuelConsumption:(NSNumber<SDLFloat> *)instantFuelConsumption {
+- (void)setInstantFuelConsumption:(nullable NSNumber<SDLFloat> *)instantFuelConsumption {
     if (instantFuelConsumption != nil) {
         [parameters setObject:instantFuelConsumption forKey:SDLNameInstantFuelConsumption];
     } else {
@@ -100,11 +100,11 @@
     }
 }
 
-- (NSNumber<SDLFloat> *)instantFuelConsumption {
+- (nullable NSNumber<SDLFloat> *)instantFuelConsumption {
     return [parameters objectForKey:SDLNameInstantFuelConsumption];
 }
 
-- (void)setExternalTemperature:(NSNumber<SDLFloat> *)externalTemperature {
+- (void)setExternalTemperature:(nullable NSNumber<SDLFloat> *)externalTemperature {
     if (externalTemperature != nil) {
         [parameters setObject:externalTemperature forKey:SDLNameExternalTemperature];
     } else {
@@ -112,11 +112,11 @@
     }
 }
 
-- (NSNumber<SDLFloat> *)externalTemperature {
+- (nullable NSNumber<SDLFloat> *)externalTemperature {
     return [parameters objectForKey:SDLNameExternalTemperature];
 }
 
-- (void)setVin:(NSString *)vin {
+- (void)setVin:(nullable NSString *)vin {
     if (vin != nil) {
         [parameters setObject:vin forKey:SDLNameVIN];
     } else {
@@ -124,11 +124,11 @@
     }
 }
 
-- (NSString *)vin {
+- (nullable NSString *)vin {
     return [parameters objectForKey:SDLNameVIN];
 }
 
-- (void)setPrndl:(SDLPRNDL)prndl {
+- (void)setPrndl:(nullable SDLPRNDL)prndl {
     if (prndl != nil) {
         [parameters setObject:prndl forKey:SDLNamePRNDL];
     } else {
@@ -136,12 +136,12 @@
     }
 }
 
-- (SDLPRNDL)prndl {
+- (nullable SDLPRNDL)prndl {
     NSObject *obj = [parameters objectForKey:SDLNamePRNDL];
     return (SDLPRNDL)obj;
 }
 
-- (void)setTirePressure:(SDLTireStatus *)tirePressure {
+- (void)setTirePressure:(nullable SDLTireStatus *)tirePressure {
     if (tirePressure != nil) {
         [parameters setObject:tirePressure forKey:SDLNameTirePressure];
     } else {
@@ -149,7 +149,7 @@
     }
 }
 
-- (SDLTireStatus *)tirePressure {
+- (nullable SDLTireStatus *)tirePressure {
     NSObject *obj = [parameters objectForKey:SDLNameTirePressure];
     if (obj == nil || [obj isKindOfClass:SDLTireStatus.class]) {
         return (SDLTireStatus *)obj;
@@ -158,7 +158,7 @@
     }
 }
 
-- (void)setOdometer:(NSNumber<SDLInt> *)odometer {
+- (void)setOdometer:(nullable NSNumber<SDLInt> *)odometer {
     if (odometer != nil) {
         [parameters setObject:odometer forKey:SDLNameOdometer];
     } else {
@@ -166,11 +166,11 @@
     }
 }
 
-- (NSNumber<SDLInt> *)odometer {
+- (nullable NSNumber<SDLInt> *)odometer {
     return [parameters objectForKey:SDLNameOdometer];
 }
 
-- (void)setBeltStatus:(SDLBeltStatus *)beltStatus {
+- (void)setBeltStatus:(nullable SDLBeltStatus *)beltStatus {
     if (beltStatus != nil) {
         [parameters setObject:beltStatus forKey:SDLNameBeltStatus];
     } else {
@@ -178,7 +178,7 @@
     }
 }
 
-- (SDLBeltStatus *)beltStatus {
+- (nullable SDLBeltStatus *)beltStatus {
     NSObject *obj = [parameters objectForKey:SDLNameBeltStatus];
     if (obj == nil || [obj isKindOfClass:SDLBeltStatus.class]) {
         return (SDLBeltStatus *)obj;
@@ -187,7 +187,7 @@
     }
 }
 
-- (void)setBodyInformation:(SDLBodyInformation *)bodyInformation {
+- (void)setBodyInformation:(nullable SDLBodyInformation *)bodyInformation {
     if (bodyInformation != nil) {
         [parameters setObject:bodyInformation forKey:SDLNameBodyInformation];
     } else {
@@ -195,7 +195,7 @@
     }
 }
 
-- (SDLBodyInformation *)bodyInformation {
+- (nullable SDLBodyInformation *)bodyInformation {
     NSObject *obj = [parameters objectForKey:SDLNameBodyInformation];
     if (obj == nil || [obj isKindOfClass:SDLBodyInformation.class]) {
         return (SDLBodyInformation *)obj;
@@ -204,7 +204,7 @@
     }
 }
 
-- (void)setDeviceStatus:(SDLDeviceStatus *)deviceStatus {
+- (void)setDeviceStatus:(nullable SDLDeviceStatus *)deviceStatus {
     if (deviceStatus != nil) {
         [parameters setObject:deviceStatus forKey:SDLNameDeviceStatus];
     } else {
@@ -212,7 +212,7 @@
     }
 }
 
-- (SDLDeviceStatus *)deviceStatus {
+- (nullable SDLDeviceStatus *)deviceStatus {
     NSObject *obj = [parameters objectForKey:SDLNameDeviceStatus];
     if (obj == nil || [obj isKindOfClass:SDLDeviceStatus.class]) {
         return (SDLDeviceStatus *)obj;
@@ -221,7 +221,7 @@
     }
 }
 
-- (void)setDriverBraking:(SDLVehicleDataEventStatus)driverBraking {
+- (void)setDriverBraking:(nullable SDLVehicleDataEventStatus)driverBraking {
     if (driverBraking != nil) {
         [parameters setObject:driverBraking forKey:SDLNameDriverBraking];
     } else {
@@ -229,12 +229,12 @@
     }
 }
 
-- (SDLVehicleDataEventStatus)driverBraking {
+- (nullable SDLVehicleDataEventStatus)driverBraking {
     NSObject *obj = [parameters objectForKey:SDLNameDriverBraking];
     return (SDLVehicleDataEventStatus)obj;
 }
 
-- (void)setWiperStatus:(SDLWiperStatus)wiperStatus {
+- (void)setWiperStatus:(nullable SDLWiperStatus)wiperStatus {
     if (wiperStatus != nil) {
         [parameters setObject:wiperStatus forKey:SDLNameWiperStatus];
     } else {
@@ -242,12 +242,12 @@
     }
 }
 
-- (SDLWiperStatus)wiperStatus {
+- (nullable SDLWiperStatus)wiperStatus {
     NSObject *obj = [parameters objectForKey:SDLNameWiperStatus];
     return (SDLWiperStatus)obj;
 }
 
-- (void)setHeadLampStatus:(SDLHeadLampStatus *)headLampStatus {
+- (void)setHeadLampStatus:(nullable SDLHeadLampStatus *)headLampStatus {
     if (headLampStatus != nil) {
         [parameters setObject:headLampStatus forKey:SDLNameHeadLampStatus];
     } else {
@@ -255,7 +255,7 @@
     }
 }
 
-- (SDLHeadLampStatus *)headLampStatus {
+- (nullable SDLHeadLampStatus *)headLampStatus {
     NSObject *obj = [parameters objectForKey:SDLNameHeadLampStatus];
     if (obj == nil || [obj isKindOfClass:SDLHeadLampStatus.class]) {
         return (SDLHeadLampStatus *)obj;
@@ -264,7 +264,7 @@
     }
 }
 
-- (void)setEngineTorque:(NSNumber<SDLFloat> *)engineTorque {
+- (void)setEngineTorque:(nullable NSNumber<SDLFloat> *)engineTorque {
     if (engineTorque != nil) {
         [parameters setObject:engineTorque forKey:SDLNameEngineTorque];
     } else {
@@ -272,11 +272,11 @@
     }
 }
 
-- (NSNumber<SDLFloat> *)engineTorque {
+- (nullable NSNumber<SDLFloat> *)engineTorque {
     return [parameters objectForKey:SDLNameEngineTorque];
 }
 
-- (void)setAccPedalPosition:(NSNumber<SDLFloat> *)accPedalPosition {
+- (void)setAccPedalPosition:(nullable NSNumber<SDLFloat> *)accPedalPosition {
     if (accPedalPosition != nil) {
         [parameters setObject:accPedalPosition forKey:SDLNameAccelerationPedalPosition];
     } else {
@@ -284,11 +284,11 @@
     }
 }
 
-- (NSNumber<SDLFloat> *)accPedalPosition {
+- (nullable NSNumber<SDLFloat> *)accPedalPosition {
     return [parameters objectForKey:SDLNameAccelerationPedalPosition];
 }
 
-- (void)setSteeringWheelAngle:(NSNumber<SDLFloat> *)steeringWheelAngle {
+- (void)setSteeringWheelAngle:(nullable NSNumber<SDLFloat> *)steeringWheelAngle {
     if (steeringWheelAngle != nil) {
         [parameters setObject:steeringWheelAngle forKey:SDLNameSteeringWheelAngle];
     } else {
@@ -296,11 +296,11 @@
     }
 }
 
-- (NSNumber<SDLFloat> *)steeringWheelAngle {
+- (nullable NSNumber<SDLFloat> *)steeringWheelAngle {
     return [parameters objectForKey:SDLNameSteeringWheelAngle];
 }
 
-- (void)setECallInfo:(SDLECallInfo *)eCallInfo {
+- (void)setECallInfo:(nullable SDLECallInfo *)eCallInfo {
     if (eCallInfo != nil) {
         [parameters setObject:eCallInfo forKey:SDLNameECallInfo];
     } else {
@@ -308,7 +308,7 @@
     }
 }
 
-- (SDLECallInfo *)eCallInfo {
+- (nullable SDLECallInfo *)eCallInfo {
     NSObject *obj = [parameters objectForKey:SDLNameECallInfo];
     if (obj == nil || [obj isKindOfClass:SDLECallInfo.class]) {
         return (SDLECallInfo *)obj;
@@ -317,7 +317,7 @@
     }
 }
 
-- (void)setAirbagStatus:(SDLAirbagStatus *)airbagStatus {
+- (void)setAirbagStatus:(nullable SDLAirbagStatus *)airbagStatus {
     if (airbagStatus != nil) {
         [parameters setObject:airbagStatus forKey:SDLNameAirbagStatus];
     } else {
@@ -325,7 +325,7 @@
     }
 }
 
-- (SDLAirbagStatus *)airbagStatus {
+- (nullable SDLAirbagStatus *)airbagStatus {
     NSObject *obj = [parameters objectForKey:SDLNameAirbagStatus];
     if (obj == nil || [obj isKindOfClass:SDLAirbagStatus.class]) {
         return (SDLAirbagStatus *)obj;
@@ -334,7 +334,7 @@
     }
 }
 
-- (void)setEmergencyEvent:(SDLEmergencyEvent *)emergencyEvent {
+- (void)setEmergencyEvent:(nullable SDLEmergencyEvent *)emergencyEvent {
     if (emergencyEvent != nil) {
         [parameters setObject:emergencyEvent forKey:SDLNameEmergencyEvent];
     } else {
@@ -342,7 +342,7 @@
     }
 }
 
-- (SDLEmergencyEvent *)emergencyEvent {
+- (nullable SDLEmergencyEvent *)emergencyEvent {
     NSObject *obj = [parameters objectForKey:SDLNameEmergencyEvent];
     if (obj == nil || [obj isKindOfClass:SDLEmergencyEvent.class]) {
         return (SDLEmergencyEvent *)obj;
@@ -351,7 +351,7 @@
     }
 }
 
-- (void)setClusterModeStatus:(SDLClusterModeStatus *)clusterModeStatus {
+- (void)setClusterModeStatus:(nullable SDLClusterModeStatus *)clusterModeStatus {
     if (clusterModeStatus != nil) {
         [parameters setObject:clusterModeStatus forKey:SDLNameClusterModeStatus];
     } else {
@@ -359,7 +359,7 @@
     }
 }
 
-- (SDLClusterModeStatus *)clusterModeStatus {
+- (nullable SDLClusterModeStatus *)clusterModeStatus {
     NSObject *obj = [parameters objectForKey:SDLNameClusterModeStatus];
     if (obj == nil || [obj isKindOfClass:SDLClusterModeStatus.class]) {
         return (SDLClusterModeStatus *)obj;
@@ -368,7 +368,7 @@
     }
 }
 
-- (void)setMyKey:(SDLMyKey *)myKey {
+- (void)setMyKey:(nullable SDLMyKey *)myKey {
     if (myKey != nil) {
         [parameters setObject:myKey forKey:SDLNameMyKey];
     } else {
@@ -376,7 +376,7 @@
     }
 }
 
-- (SDLMyKey *)myKey {
+- (nullable SDLMyKey *)myKey {
     NSObject *obj = [parameters objectForKey:SDLNameMyKey];
     if (obj == nil || [obj isKindOfClass:SDLMyKey.class]) {
         return (SDLMyKey *)obj;
diff --git a/SmartDeviceLink/SDLGetWaypointsResponse.h b/SmartDeviceLink/SDLGetWaypointsResponse.h
index 94d449886..cf09a2300 100644
--- a/SmartDeviceLink/SDLGetWaypointsResponse.h
+++ b/SmartDeviceLink/SDLGetWaypointsResponse.h
@@ -5,6 +5,8 @@
 
 @class SDLLocationDetails;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLGetWaypointsResponse : SDLRPCResponse
 
 /**
@@ -14,6 +16,8 @@
  *
  * Optional, Array size 1 - 10
  */
-@property (strong) NSArray<SDLLocationDetails *> *waypoints;
+@property (nullable, strong) NSArray<SDLLocationDetails *> *waypoints;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetWaypointsResponse.m b/SmartDeviceLink/SDLGetWaypointsResponse.m
index 7a49ad886..e0dbddc46 100644
--- a/SmartDeviceLink/SDLGetWaypointsResponse.m
+++ b/SmartDeviceLink/SDLGetWaypointsResponse.m
@@ -12,7 +12,7 @@
     return self;
 }
 
-- (void)setWaypoints:(NSArray<SDLLocationDetails *> *)waypoints {
+- (void)setWaypoints:(nullable NSArray<SDLLocationDetails *> *)waypoints {
     if (waypoints != nil) {
         parameters[SDLNameWaypoints] = waypoints;
     } else {
@@ -20,7 +20,7 @@
     }
 }
 
-- (NSArray<SDLLocationDetails *> *)waypoints {
+- (nullable NSArray<SDLLocationDetails *> *)waypoints {
     return parameters[SDLNameWaypoints];
 }
 
diff --git a/SmartDeviceLink/SDLListFilesResponse.h b/SmartDeviceLink/SDLListFilesResponse.h
index 47e6b3176..cd8fb1a63 100644
--- a/SmartDeviceLink/SDLListFilesResponse.h
+++ b/SmartDeviceLink/SDLListFilesResponse.h
@@ -9,9 +9,14 @@
  *
  * Since <b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLListFilesResponse : SDLRPCResponse
 
-@property (strong) NSMutableArray<NSString *> *filenames;
+@property (nullable, strong) NSMutableArray<NSString *> *filenames;
 @property (strong) NSNumber<SDLInt> *spaceAvailable;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLListFilesResponse.m b/SmartDeviceLink/SDLListFilesResponse.m
index 2e7f0dc8f..6a86eab1b 100644
--- a/SmartDeviceLink/SDLListFilesResponse.m
+++ b/SmartDeviceLink/SDLListFilesResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLListFilesResponse
 
 - (instancetype)init {
@@ -14,7 +16,7 @@
     return self;
 }
 
-- (void)setFilenames:(NSMutableArray<NSString *> *)filenames {
+- (void)setFilenames:(nullable NSMutableArray<NSString *> *)filenames {
     if (filenames != nil) {
         [parameters setObject:filenames forKey:SDLNameFilenames];
     } else {
@@ -22,7 +24,7 @@
     }
 }
 
-- (NSMutableArray<NSString *> *)filenames {
+- (nullable NSMutableArray<NSString *> *)filenames {
     return [parameters objectForKey:SDLNameFilenames];
 }
 
@@ -39,3 +41,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformAudioPassThruResponse.h b/SmartDeviceLink/SDLPerformAudioPassThruResponse.h
index c187f0c78..853a566bc 100644
--- a/SmartDeviceLink/SDLPerformAudioPassThruResponse.h
+++ b/SmartDeviceLink/SDLPerformAudioPassThruResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPerformAudioPassThruResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformAudioPassThruResponse.m b/SmartDeviceLink/SDLPerformAudioPassThruResponse.m
index 386b91c50..dec6fbd88 100644
--- a/SmartDeviceLink/SDLPerformAudioPassThruResponse.m
+++ b/SmartDeviceLink/SDLPerformAudioPassThruResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLPerformAudioPassThruResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformInteractionResponse.h b/SmartDeviceLink/SDLPerformInteractionResponse.h
index b04bd0f7f..0d308a6cf 100644
--- a/SmartDeviceLink/SDLPerformInteractionResponse.h
+++ b/SmartDeviceLink/SDLPerformInteractionResponse.h
@@ -11,6 +11,9 @@
  *
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPerformInteractionResponse : SDLRPCResponse
 
 /**
@@ -20,7 +23,7 @@
  *
  * Optional, Integer, 0 - 2,000,000,000
  */
-@property (strong) NSNumber<SDLInt> *choiceID;
+@property (nullable, strong) NSNumber<SDLInt> *choiceID;
 
 /**
  * @abstract Manually entered text selection, e.g. through keyboard
@@ -29,14 +32,16 @@
  *
  * Optional, Max length 500 chars
  */
-@property (strong) NSString *manualTextEntry;
+@property (nullable, strong) NSString *manualTextEntry;
 
 /**
  * @abstract A *SDLTriggerSource* object which will be shown in the HMI
  *
  * @discussion Only is valid if resultCode is SUCCESS.
  */
-@property (strong) SDLTriggerSource triggerSource;
+@property (nullable, strong) SDLTriggerSource triggerSource;
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformInteractionResponse.m b/SmartDeviceLink/SDLPerformInteractionResponse.m
index 077fd7386..f606848f2 100644
--- a/SmartDeviceLink/SDLPerformInteractionResponse.m
+++ b/SmartDeviceLink/SDLPerformInteractionResponse.m
@@ -14,7 +14,7 @@
     return self;
 }
 
-- (void)setChoiceID:(NSNumber<SDLInt> *)choiceID {
+- (void)setChoiceID:(nullable NSNumber<SDLInt> *)choiceID {
     if (choiceID != nil) {
         [parameters setObject:choiceID forKey:SDLNameChoiceId];
     } else {
@@ -22,11 +22,11 @@
     }
 }
 
-- (NSNumber<SDLInt> *)choiceID {
+- (nullable NSNumber<SDLInt> *)choiceID {
     return [parameters objectForKey:SDLNameChoiceId];
 }
 
-- (void)setManualTextEntry:(NSString *)manualTextEntry {
+- (void)setManualTextEntry:(nullable NSString *)manualTextEntry {
     if (manualTextEntry != nil) {
         [parameters setObject:manualTextEntry forKey:SDLNameManualTextEntry];
     } else {
@@ -34,11 +34,11 @@
     }
 }
 
-- (NSString *)manualTextEntry {
+- (nullable NSString *)manualTextEntry {
     return [parameters objectForKey:SDLNameManualTextEntry];
 }
 
-- (void)setTriggerSource:(SDLTriggerSource)triggerSource {
+- (void)setTriggerSource:(nullable SDLTriggerSource)triggerSource {
     if (triggerSource != nil) {
         [parameters setObject:triggerSource forKey:SDLNameTriggerSource];
     } else {
@@ -46,7 +46,7 @@
     }
 }
 
-- (SDLTriggerSource)triggerSource {
+- (nullable SDLTriggerSource)triggerSource {
     NSObject *obj = [parameters objectForKey:SDLNameTriggerSource];
     return (SDLTriggerSource)obj;
 }
diff --git a/SmartDeviceLink/SDLPutFileResponse.h b/SmartDeviceLink/SDLPutFileResponse.h
index 408ac87a8..3b85e2f66 100644
--- a/SmartDeviceLink/SDLPutFileResponse.h
+++ b/SmartDeviceLink/SDLPutFileResponse.h
@@ -9,7 +9,12 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPutFileResponse : SDLRPCResponse
 
 @property (strong) NSNumber<SDLInt> *spaceAvailable;
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPutFileResponse.m b/SmartDeviceLink/SDLPutFileResponse.m
index d4d458c65..e392a2932 100644
--- a/SmartDeviceLink/SDLPutFileResponse.m
+++ b/SmartDeviceLink/SDLPutFileResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLPutFileResponse
 
 - (instancetype)init {
@@ -27,3 +29,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLReadDIDResponse.h b/SmartDeviceLink/SDLReadDIDResponse.h
index 0c9668bf9..8b8710656 100644
--- a/SmartDeviceLink/SDLReadDIDResponse.h
+++ b/SmartDeviceLink/SDLReadDIDResponse.h
@@ -11,8 +11,13 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLReadDIDResponse : SDLRPCResponse
 
-@property (strong) NSMutableArray<SDLDIDResult *> *didResult;
+@property (nullable, strong) NSMutableArray<SDLDIDResult *> *didResult;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLReadDIDResponse.m b/SmartDeviceLink/SDLReadDIDResponse.m
index ff8aae51b..48651fff1 100644
--- a/SmartDeviceLink/SDLReadDIDResponse.m
+++ b/SmartDeviceLink/SDLReadDIDResponse.m
@@ -15,7 +15,7 @@
     return self;
 }
 
-- (void)setDidResult:(NSMutableArray<SDLDIDResult *> *)didResult {
+- (void)setDidResult:(nullable NSMutableArray<SDLDIDResult *> *)didResult {
     if (didResult != nil) {
         [parameters setObject:didResult forKey:SDLNameDIDResult];
     } else {
@@ -23,7 +23,7 @@
     }
 }
 
-- (NSMutableArray<SDLDIDResult *> *)didResult {
+- (nullable NSMutableArray<SDLDIDResult *> *)didResult {
     NSMutableArray<SDLDIDResult *> *array = [parameters objectForKey:SDLNameDIDResult];
     if ([array count] < 1 || [[array objectAtIndex:0] isKindOfClass:SDLDIDResult.class]) {
         return array;
diff --git a/SmartDeviceLink/SDLRegisterAppInterfaceResponse.h b/SmartDeviceLink/SDLRegisterAppInterfaceResponse.h
index aac85c457..782a68908 100644
--- a/SmartDeviceLink/SDLRegisterAppInterfaceResponse.h
+++ b/SmartDeviceLink/SDLRegisterAppInterfaceResponse.h
@@ -25,6 +25,9 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLRegisterAppInterfaceResponse : SDLRPCResponse
 
 /**
@@ -32,7 +35,7 @@
  *
  * Optional
  */
-@property (strong) SDLSyncMsgVersion *syncMsgVersion;
+@property (nullable, strong) SDLSyncMsgVersion *syncMsgVersion;
 
 /**
  * The currently active VR+TTS language on Sync.
@@ -41,7 +44,7 @@
  *
  * Optional
  */
-@property (strong) SDLLanguage language;
+@property (nullable, strong) SDLLanguage language;
 
 /**
  * The currently active display language on Sync
@@ -51,21 +54,21 @@
  *
  * Optional
  */
-@property (strong) SDLLanguage hmiDisplayLanguage;
+@property (nullable, strong) SDLLanguage hmiDisplayLanguage;
 
 /**
  * @see SDLDisplayCapabilities
  *
  * Optional
  */
-@property (strong) SDLDisplayCapabilities *displayCapabilities;
+@property (nullable, strong) SDLDisplayCapabilities *displayCapabilities;
 
 /**
  * @see SDLButtonCapabilities
  *
  * Optional, Array of length 1 - 100, of SDLButtonCapabilities
  */
-@property (strong) NSMutableArray<SDLButtonCapabilities *> *buttonCapabilities;
+@property (nullable, strong) NSMutableArray<SDLButtonCapabilities *> *buttonCapabilities;
 
 /**
  * If returned, the platform supports on-screen SoftButtons
@@ -74,7 +77,7 @@
  *
  * Optional, Array of length 1 - 100, of SDLSoftButtonCapabilities
  */
-@property (strong) NSMutableArray<SDLSoftButtonCapabilities *> *softButtonCapabilities;
+@property (nullable, strong) NSMutableArray<SDLSoftButtonCapabilities *> *softButtonCapabilities;
 
 /**
  * If returned, the platform supports custom on-screen Presets
@@ -83,42 +86,42 @@
  *
  * Optional
  */
-@property (strong) SDLPresetBankCapabilities *presetBankCapabilities;
+@property (nullable, strong) SDLPresetBankCapabilities *presetBankCapabilities;
 
 /**
  * @see SDLHMIZoneCapabilities
  *
  * Optional, Array of length 1 - 100, of SDLHMIZoneCapabilities
  */
-@property (strong) NSMutableArray<SDLHMIZoneCapabilities> *hmiZoneCapabilities;
+@property (nullable, strong) NSMutableArray<SDLHMIZoneCapabilities> *hmiZoneCapabilities;
 
 /**
  * @see SDLSpeechCapabilities
  *
  * Optional, Array of length 1 - 100, of SDLSpeechCapabilities
  */
-@property (strong) NSMutableArray<SDLSpeechCapabilities> *speechCapabilities;
+@property (nullable, strong) NSMutableArray<SDLSpeechCapabilities> *speechCapabilities;
 
 /**
  * @see SDLPrerecordedSpeech
  *
  * Optional, Array of length 1 - 100, of SDLPrerecordedSpeech
  */
-@property (strong) NSMutableArray<SDLPrerecordedSpeech> *prerecordedSpeech;
+@property (nullable, strong) NSMutableArray<SDLPrerecordedSpeech> *prerecordedSpeech;
 
 /**
  * @see SDLVRCapabilities
  *
  * Optional, Array of length 1 - 100, of SDLVRCapabilities
  */
-@property (strong) NSMutableArray<SDLVRCapabilities> *vrCapabilities;
+@property (nullable, strong) NSMutableArray<SDLVRCapabilities> *vrCapabilities;
 
 /**
  * @see SDLAudioPassThruCapabilities
  *
  * Optional, Array of length 1 - 100, of SDLAudioPassThruCapabilities
  */
-@property (strong) NSMutableArray<SDLAudioPassThruCapabilities *> *audioPassThruCapabilities;
+@property (nullable, strong) NSMutableArray<SDLAudioPassThruCapabilities *> *audioPassThruCapabilities;
 
 /**
  * Specifies the vehicle's type
@@ -127,35 +130,37 @@
  *
  * Optional, Array of length 1 - 100, of SDLVehicleType
  */
-@property (strong) SDLVehicleType *vehicleType;
+@property (nullable, strong) SDLVehicleType *vehicleType;
 
 /**
  * Specifies the white-list of supported diagnostic modes (0x00-0xFF) capable for DiagnosticMessage requests. If a mode outside this list is requested, it will be rejected.
  *
  * Optional, Array of length 1 - 100, Integer 0 - 255
  */
-@property (strong) NSMutableArray<NSNumber<SDLInt> *> *supportedDiagModes;
+@property (nullable, strong) NSMutableArray<NSNumber<SDLInt> *> *supportedDiagModes;
 
 /**
  * @see SDLHMICapabilities
  *
  * Optional
  */
-@property (strong) SDLHMICapabilities *hmiCapabilities;
+@property (nullable, strong) SDLHMICapabilities *hmiCapabilities;
 
 /**
  * The SmartDeviceLink version
  *
  * Optional, String max length 100
  */
-@property (strong) NSString *sdlVersion;
+@property (nullable, strong) NSString *sdlVersion;
 
 /**
  * The software version of the system that implements the SmartDeviceLink core
  *
  * Optional, String max length 100
  */
-@property (strong) NSString *systemSoftwareVersion;
+@property (nullable, strong) NSString *systemSoftwareVersion;
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRegisterAppInterfaceResponse.m b/SmartDeviceLink/SDLRegisterAppInterfaceResponse.m
index fb65628ca..ad0a66485 100644
--- a/SmartDeviceLink/SDLRegisterAppInterfaceResponse.m
+++ b/SmartDeviceLink/SDLRegisterAppInterfaceResponse.m
@@ -22,7 +22,7 @@
     return self;
 }
 
-- (void)setSyncMsgVersion:(SDLSyncMsgVersion *)syncMsgVersion {
+- (void)setSyncMsgVersion:(nullable SDLSyncMsgVersion *)syncMsgVersion {
     if (syncMsgVersion != nil) {
         [parameters setObject:syncMsgVersion forKey:SDLNameSyncMessageVersion];
     } else {
@@ -30,7 +30,7 @@
     }
 }
 
-- (SDLSyncMsgVersion *)syncMsgVersion {
+- (nullable SDLSyncMsgVersion *)syncMsgVersion {
     NSObject *obj = [parameters objectForKey:SDLNameSyncMessageVersion];
     if (obj == nil || [obj isKindOfClass:SDLSyncMsgVersion.class]) {
         return (SDLSyncMsgVersion *)obj;
@@ -39,7 +39,7 @@
     }
 }
 
-- (void)setLanguage:(SDLLanguage)language {
+- (void)setLanguage:(nullable SDLLanguage)language {
     if (language != nil) {
         [parameters setObject:language forKey:SDLNameLanguage];
     } else {
@@ -47,12 +47,12 @@
     }
 }
 
-- (SDLLanguage)language {
+- (nullable SDLLanguage)language {
     NSObject *obj = [parameters objectForKey:SDLNameLanguage];
     return (SDLLanguage)obj;
 }
 
-- (void)setHmiDisplayLanguage:(SDLLanguage)hmiDisplayLanguage {
+- (void)setHmiDisplayLanguage:(nullable SDLLanguage)hmiDisplayLanguage {
     if (hmiDisplayLanguage != nil) {
         [parameters setObject:hmiDisplayLanguage forKey:SDLNameHMIDisplayLanguage];
     } else {
@@ -60,12 +60,12 @@
     }
 }
 
-- (SDLLanguage)hmiDisplayLanguage {
+- (nullable SDLLanguage)hmiDisplayLanguage {
     NSObject *obj = [parameters objectForKey:SDLNameHMIDisplayLanguage];
     return (SDLLanguage)obj;
 }
 
-- (void)setDisplayCapabilities:(SDLDisplayCapabilities *)displayCapabilities {
+- (void)setDisplayCapabilities:(nullable SDLDisplayCapabilities *)displayCapabilities {
     if (displayCapabilities != nil) {
         [parameters setObject:displayCapabilities forKey:SDLNameDisplayCapabilities];
     } else {
@@ -73,7 +73,7 @@
     }
 }
 
-- (SDLDisplayCapabilities *)displayCapabilities {
+- (nullable SDLDisplayCapabilities *)displayCapabilities {
     NSObject *obj = [parameters objectForKey:SDLNameDisplayCapabilities];
     if (obj == nil || [obj isKindOfClass:SDLDisplayCapabilities.class]) {
         return (SDLDisplayCapabilities *)obj;
@@ -82,7 +82,7 @@
     }
 }
 
-- (void)setButtonCapabilities:(NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
+- (void)setButtonCapabilities:(nullable NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
     if (buttonCapabilities != nil) {
         [parameters setObject:buttonCapabilities forKey:SDLNameButtonCapabilities];
     } else {
@@ -90,7 +90,7 @@
     }
 }
 
-- (NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
+- (nullable NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
     NSMutableArray<SDLButtonCapabilities *> *array = [parameters objectForKey:SDLNameButtonCapabilities];
     if ([array count] < 1 || [[array objectAtIndex:0] isKindOfClass:SDLButtonCapabilities.class]) {
         return array;
@@ -103,7 +103,7 @@
     }
 }
 
-- (void)setSoftButtonCapabilities:(NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
+- (void)setSoftButtonCapabilities:(nullable NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
     if (softButtonCapabilities != nil) {
         [parameters setObject:softButtonCapabilities forKey:SDLNameSoftButtonCapabilities];
     } else {
@@ -111,7 +111,7 @@
     }
 }
 
-- (NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
+- (nullable NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
     NSMutableArray<SDLSoftButtonCapabilities *> *array = [parameters objectForKey:SDLNameSoftButtonCapabilities];
     if ([array count] < 1 || [[array objectAtIndex:0] isKindOfClass:SDLSoftButtonCapabilities.class]) {
         return array;
@@ -124,7 +124,7 @@
     }
 }
 
-- (void)setPresetBankCapabilities:(SDLPresetBankCapabilities *)presetBankCapabilities {
+- (void)setPresetBankCapabilities:(nullable SDLPresetBankCapabilities *)presetBankCapabilities {
     if (presetBankCapabilities != nil) {
         [parameters setObject:presetBankCapabilities forKey:SDLNamePresetBankCapabilities];
     } else {
@@ -132,7 +132,7 @@
     }
 }
 
-- (SDLPresetBankCapabilities *)presetBankCapabilities {
+- (nullable SDLPresetBankCapabilities *)presetBankCapabilities {
     NSObject *obj = [parameters objectForKey:SDLNamePresetBankCapabilities];
     if (obj == nil || [obj isKindOfClass:SDLPresetBankCapabilities.class]) {
         return (SDLPresetBankCapabilities *)obj;
@@ -141,7 +141,7 @@
     }
 }
 
-- (void)setHmiZoneCapabilities:(NSMutableArray<SDLHMIZoneCapabilities> *)hmiZoneCapabilities {
+- (void)setHmiZoneCapabilities:(nullable NSMutableArray<SDLHMIZoneCapabilities> *)hmiZoneCapabilities {
     if (hmiZoneCapabilities != nil) {
         [parameters setObject:hmiZoneCapabilities forKey:SDLNameHMIZoneCapabilities];
     } else {
@@ -149,7 +149,7 @@
     }
 }
 
-- (NSMutableArray<SDLHMIZoneCapabilities> *)hmiZoneCapabilities {
+- (nullable NSMutableArray<SDLHMIZoneCapabilities> *)hmiZoneCapabilities {
     NSMutableArray<SDLHMIZoneCapabilities> *array = [parameters objectForKey:SDLNameHMIZoneCapabilities];
     if ([array count] < 1) {
         return array;
@@ -162,7 +162,7 @@
     }
 }
 
-- (void)setSpeechCapabilities:(NSMutableArray<SDLSpeechCapabilities> *)speechCapabilities {
+- (void)setSpeechCapabilities:(nullable NSMutableArray<SDLSpeechCapabilities> *)speechCapabilities {
     if (speechCapabilities != nil) {
         [parameters setObject:speechCapabilities forKey:SDLNameSpeechCapabilities];
     } else {
@@ -170,7 +170,7 @@
     }
 }
 
-- (NSMutableArray<SDLSpeechCapabilities> *)speechCapabilities {
+- (nullable NSMutableArray<SDLSpeechCapabilities> *)speechCapabilities {
     NSMutableArray<SDLSpeechCapabilities> *array = [parameters objectForKey:SDLNameSpeechCapabilities];
     if ([array count] < 1) {
         return array;
@@ -183,7 +183,7 @@
     }
 }
 
-- (void)setPrerecordedSpeech:(NSMutableArray<SDLPrerecordedSpeech> *)prerecordedSpeech {
+- (void)setPrerecordedSpeech:(nullable NSMutableArray<SDLPrerecordedSpeech> *)prerecordedSpeech {
     if (prerecordedSpeech != nil) {
         [parameters setObject:prerecordedSpeech forKey:SDLNamePrerecordedSpeech];
     } else {
@@ -191,7 +191,7 @@
     }
 }
 
-- (NSMutableArray<SDLPrerecordedSpeech> *)prerecordedSpeech {
+- (nullable NSMutableArray<SDLPrerecordedSpeech> *)prerecordedSpeech {
     NSMutableArray<SDLPrerecordedSpeech> *array = [parameters objectForKey:SDLNamePrerecordedSpeech];
     if ([array count] < 1) {
         return array;
@@ -204,7 +204,7 @@
     }
 }
 
-- (void)setVrCapabilities:(NSMutableArray<SDLVRCapabilities> *)vrCapabilities {
+- (void)setVrCapabilities:(nullable NSMutableArray<SDLVRCapabilities> *)vrCapabilities {
     if (vrCapabilities != nil) {
         [parameters setObject:vrCapabilities forKey:SDLNameVRCapabilities];
     } else {
@@ -212,7 +212,7 @@
     }
 }
 
-- (NSMutableArray<SDLVRCapabilities> *)vrCapabilities {
+- (nullable NSMutableArray<SDLVRCapabilities> *)vrCapabilities {
     NSMutableArray<SDLVRCapabilities> *array = [parameters objectForKey:SDLNameVRCapabilities];
     if ([array count] < 1) {
         return array;
@@ -225,7 +225,7 @@
     }
 }
 
-- (void)setAudioPassThruCapabilities:(NSMutableArray<SDLAudioPassThruCapabilities *> *)audioPassThruCapabilities {
+- (void)setAudioPassThruCapabilities:(nullable NSMutableArray<SDLAudioPassThruCapabilities *> *)audioPassThruCapabilities {
     if (audioPassThruCapabilities != nil) {
         [parameters setObject:audioPassThruCapabilities forKey:SDLNameAudioPassThruCapabilities];
     } else {
@@ -233,7 +233,7 @@
     }
 }
 
-- (NSMutableArray<SDLAudioPassThruCapabilities *> *)audioPassThruCapabilities {
+- (nullable NSMutableArray<SDLAudioPassThruCapabilities *> *)audioPassThruCapabilities {
     NSMutableArray<SDLAudioPassThruCapabilities *> *array = [parameters objectForKey:SDLNameAudioPassThruCapabilities];
     if ([array count] < 1 || [[array objectAtIndex:0] isKindOfClass:SDLAudioPassThruCapabilities.class]) {
         return array;
@@ -246,7 +246,7 @@
     }
 }
 
-- (void)setVehicleType:(SDLVehicleType *)vehicleType {
+- (void)setVehicleType:(nullable SDLVehicleType *)vehicleType {
     if (vehicleType != nil) {
         [parameters setObject:vehicleType forKey:SDLNameVehicleType];
     } else {
@@ -254,7 +254,7 @@
     }
 }
 
-- (SDLVehicleType *)vehicleType {
+- (nullable SDLVehicleType *)vehicleType {
     NSObject *obj = [parameters objectForKey:SDLNameVehicleType];
     if (obj == nil || [obj isKindOfClass:SDLVehicleType.class]) {
         return (SDLVehicleType *)obj;
@@ -263,7 +263,7 @@
     }
 }
 
-- (void)setSupportedDiagModes:(NSMutableArray<NSNumber<SDLInt> *> *)supportedDiagModes {
+- (void)setSupportedDiagModes:(nullable NSMutableArray<NSNumber<SDLInt> *> *)supportedDiagModes {
     if (supportedDiagModes != nil) {
         [parameters setObject:supportedDiagModes forKey:SDLNameSupportedDiagnosticModes];
     } else {
@@ -271,11 +271,11 @@
     }
 }
 
-- (NSMutableArray<NSNumber<SDLInt> *> *)supportedDiagModes {
+- (nullable NSMutableArray<NSNumber<SDLInt> *> *)supportedDiagModes {
     return [parameters objectForKey:SDLNameSupportedDiagnosticModes];
 }
 
-- (void)setHmiCapabilities:(SDLHMICapabilities *)hmiCapabilities {
+- (void)setHmiCapabilities:(nullable SDLHMICapabilities *)hmiCapabilities {
     if (hmiCapabilities != nil) {
         [parameters setObject:hmiCapabilities forKey:SDLNameHMICapabilities];
     } else {
@@ -283,7 +283,7 @@
     }
 }
 
-- (SDLHMICapabilities *)hmiCapabilities {
+- (nullable SDLHMICapabilities *)hmiCapabilities {
     NSObject *obj = [parameters objectForKey:SDLNameHMICapabilities];
     if (obj == nil || [obj isKindOfClass:[SDLHMICapabilities class]]) {
         return (SDLHMICapabilities *)obj;
@@ -292,7 +292,7 @@
     }
 }
 
-- (void)setSdlVersion:(NSString *)sdlVersion {
+- (void)setSdlVersion:(nullable NSString *)sdlVersion {
     if (sdlVersion != nil) {
         parameters[SDLNameSDLVersion] = sdlVersion;
     } else {
@@ -300,11 +300,11 @@
     }
 }
 
-- (NSString *)sdlVersion {
+- (nullable NSString *)sdlVersion {
     return parameters[SDLNameSDLVersion];
 }
 
-- (void)setSystemSoftwareVersion:(NSString *)systemSoftwareVersion {
+- (void)setSystemSoftwareVersion:(nullable NSString *)systemSoftwareVersion {
     if (systemSoftwareVersion != nil) {
         parameters[SDLNameSystemSoftwareVersion] = systemSoftwareVersion;
     } else {
@@ -312,7 +312,7 @@
     }
 }
 
-- (NSString *)systemSoftwareVersion {
+- (nullable NSString *)systemSoftwareVersion {
     return parameters[SDLNameSystemSoftwareVersion];
 }
 
diff --git a/SmartDeviceLink/SDLResetGlobalPropertiesResponse.h b/SmartDeviceLink/SDLResetGlobalPropertiesResponse.h
index eda1b2628..23a043cd6 100644
--- a/SmartDeviceLink/SDLResetGlobalPropertiesResponse.h
+++ b/SmartDeviceLink/SDLResetGlobalPropertiesResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLResetGlobalPropertiesResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLResetGlobalPropertiesResponse.m b/SmartDeviceLink/SDLResetGlobalPropertiesResponse.m
index 0ae8c079d..30b85e13a 100644
--- a/SmartDeviceLink/SDLResetGlobalPropertiesResponse.m
+++ b/SmartDeviceLink/SDLResetGlobalPropertiesResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLResetGlobalPropertiesResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLScrollableMessageResponse.h b/SmartDeviceLink/SDLScrollableMessageResponse.h
index 516415468..4f6d17a8a 100644
--- a/SmartDeviceLink/SDLScrollableMessageResponse.h
+++ b/SmartDeviceLink/SDLScrollableMessageResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLScrollableMessageResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSendLocationResponse.h b/SmartDeviceLink/SDLSendLocationResponse.h
index 35fc2eca1..8059bc1b2 100644
--- a/SmartDeviceLink/SDLSendLocationResponse.h
+++ b/SmartDeviceLink/SDLSendLocationResponse.h
@@ -4,6 +4,10 @@
 
 #import "SDLRPCResponse.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSendLocationResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSendLocationResponse.m b/SmartDeviceLink/SDLSendLocationResponse.m
index 08e47b71f..db339e753 100644
--- a/SmartDeviceLink/SDLSendLocationResponse.m
+++ b/SmartDeviceLink/SDLSendLocationResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSendLocationResponse
 
 - (instancetype)init {
@@ -18,3 +20,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetAppIconResponse.h b/SmartDeviceLink/SDLSetAppIconResponse.h
index 28c818782..ba189dc4d 100644
--- a/SmartDeviceLink/SDLSetAppIconResponse.h
+++ b/SmartDeviceLink/SDLSetAppIconResponse.h
@@ -7,6 +7,11 @@
 /** SDLSetAppIconResponse is sent, when SDLSetAppIcon has been called.
  * Since<b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetAppIconResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetAppIconResponse.m b/SmartDeviceLink/SDLSetAppIconResponse.m
index 9469b3b99..c5126ee30 100644
--- a/SmartDeviceLink/SDLSetAppIconResponse.m
+++ b/SmartDeviceLink/SDLSetAppIconResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSetAppIconResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetDisplayLayoutResponse.h b/SmartDeviceLink/SDLSetDisplayLayoutResponse.h
index 1beff1419..c98d1bf3b 100644
--- a/SmartDeviceLink/SDLSetDisplayLayoutResponse.h
+++ b/SmartDeviceLink/SDLSetDisplayLayoutResponse.h
@@ -13,11 +13,16 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetDisplayLayoutResponse : SDLRPCResponse
 
-@property (strong) SDLDisplayCapabilities *displayCapabilities;
-@property (strong) NSMutableArray<SDLButtonCapabilities *> *buttonCapabilities;
-@property (strong) NSMutableArray<SDLSoftButtonCapabilities *> *softButtonCapabilities;
-@property (strong) SDLPresetBankCapabilities *presetBankCapabilities;
+@property (nullable, strong) SDLDisplayCapabilities *displayCapabilities;
+@property (nullable, strong) NSMutableArray<SDLButtonCapabilities *> *buttonCapabilities;
+@property (nullable, strong) NSMutableArray<SDLSoftButtonCapabilities *> *softButtonCapabilities;
+@property (nullable, strong) SDLPresetBankCapabilities *presetBankCapabilities;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetDisplayLayoutResponse.m b/SmartDeviceLink/SDLSetDisplayLayoutResponse.m
index fe5d5c6ba..553faf122 100644
--- a/SmartDeviceLink/SDLSetDisplayLayoutResponse.m
+++ b/SmartDeviceLink/SDLSetDisplayLayoutResponse.m
@@ -18,7 +18,7 @@
     return self;
 }
 
-- (void)setDisplayCapabilities:(SDLDisplayCapabilities *)displayCapabilities {
+- (void)setDisplayCapabilities:(nullable SDLDisplayCapabilities *)displayCapabilities {
     if (displayCapabilities != nil) {
         [parameters setObject:displayCapabilities forKey:SDLNameDisplayCapabilities];
     } else {
@@ -26,7 +26,7 @@
     }
 }
 
-- (SDLDisplayCapabilities *)displayCapabilities {
+- (nullable SDLDisplayCapabilities *)displayCapabilities {
     NSObject *obj = [parameters objectForKey:SDLNameDisplayCapabilities];
     if (obj == nil || [obj isKindOfClass:SDLDisplayCapabilities.class]) {
         return (SDLDisplayCapabilities *)obj;
@@ -35,7 +35,7 @@
     }
 }
 
-- (void)setButtonCapabilities:(NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
+- (void)setButtonCapabilities:(nullable NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
     if (buttonCapabilities != nil) {
         [parameters setObject:buttonCapabilities forKey:SDLNameButtonCapabilities];
     } else {
@@ -43,7 +43,7 @@
     }
 }
 
-- (NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
+- (nullable NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
     NSMutableArray<SDLButtonCapabilities *> *array = [parameters objectForKey:SDLNameButtonCapabilities];
     if ([array count] < 1 || [[array objectAtIndex:0] isKindOfClass:SDLButtonCapabilities.class]) {
         return array;
@@ -56,7 +56,7 @@
     }
 }
 
-- (void)setSoftButtonCapabilities:(NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
+- (void)setSoftButtonCapabilities:(nullable NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
     if (softButtonCapabilities != nil) {
         [parameters setObject:softButtonCapabilities forKey:SDLNameSoftButtonCapabilities];
     } else {
@@ -64,7 +64,7 @@
     }
 }
 
-- (NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
+- (nullable NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
     NSMutableArray<SDLSoftButtonCapabilities *> *array = [parameters objectForKey:SDLNameSoftButtonCapabilities];
     if ([array count] < 1 || [[array objectAtIndex:0] isKindOfClass:SDLSoftButtonCapabilities.class]) {
         return array;
@@ -77,7 +77,7 @@
     }
 }
 
-- (void)setPresetBankCapabilities:(SDLPresetBankCapabilities *)presetBankCapabilities {
+- (void)setPresetBankCapabilities:(nullable SDLPresetBankCapabilities *)presetBankCapabilities {
     if (presetBankCapabilities != nil) {
         [parameters setObject:presetBankCapabilities forKey:SDLNamePresetBankCapabilities];
     } else {
@@ -85,7 +85,7 @@
     }
 }
 
-- (SDLPresetBankCapabilities *)presetBankCapabilities {
+- (nullable SDLPresetBankCapabilities *)presetBankCapabilities {
     NSObject *obj = [parameters objectForKey:SDLNamePresetBankCapabilities];
     if (obj == nil || [obj isKindOfClass:SDLPresetBankCapabilities.class]) {
         return (SDLPresetBankCapabilities *)obj;
diff --git a/SmartDeviceLink/SDLSetGlobalPropertiesResponse.h b/SmartDeviceLink/SDLSetGlobalPropertiesResponse.h
index a5dd82139..f41991d53 100644
--- a/SmartDeviceLink/SDLSetGlobalPropertiesResponse.h
+++ b/SmartDeviceLink/SDLSetGlobalPropertiesResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetGlobalPropertiesResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetGlobalPropertiesResponse.m b/SmartDeviceLink/SDLSetGlobalPropertiesResponse.m
index 4b56322ac..3ae2e6591 100644
--- a/SmartDeviceLink/SDLSetGlobalPropertiesResponse.m
+++ b/SmartDeviceLink/SDLSetGlobalPropertiesResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSetGlobalPropertiesResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetMediaClockTimerResponse.h b/SmartDeviceLink/SDLSetMediaClockTimerResponse.h
index d1adbda4d..54a599821 100644
--- a/SmartDeviceLink/SDLSetMediaClockTimerResponse.h
+++ b/SmartDeviceLink/SDLSetMediaClockTimerResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetMediaClockTimerResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetMediaClockTimerResponse.m b/SmartDeviceLink/SDLSetMediaClockTimerResponse.m
index 899fc4926..b976ba119 100644
--- a/SmartDeviceLink/SDLSetMediaClockTimerResponse.m
+++ b/SmartDeviceLink/SDLSetMediaClockTimerResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSetMediaClockTimerResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShowConstantTBTResponse.h b/SmartDeviceLink/SDLShowConstantTBTResponse.h
index 8af3a9f23..b6c196734 100644
--- a/SmartDeviceLink/SDLShowConstantTBTResponse.h
+++ b/SmartDeviceLink/SDLShowConstantTBTResponse.h
@@ -7,6 +7,11 @@
 /** SDLShowConstantTBTResponse is sent, when SDLShowConstantTBT has been called.
  * Since<b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLShowConstantTBTResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShowConstantTBTResponse.m b/SmartDeviceLink/SDLShowConstantTBTResponse.m
index ee0d4f36e..0327f0420 100644
--- a/SmartDeviceLink/SDLShowConstantTBTResponse.m
+++ b/SmartDeviceLink/SDLShowConstantTBTResponse.m
@@ -5,6 +5,8 @@
 #import "SDLShowConstantTBTResponse.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLShowConstantTBTResponse
 
 - (instancetype)init {
@@ -14,3 +16,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShowResponse.h b/SmartDeviceLink/SDLShowResponse.h
index 1963390ec..0cb87e942 100644
--- a/SmartDeviceLink/SDLShowResponse.h
+++ b/SmartDeviceLink/SDLShowResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLShowResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShowResponse.m b/SmartDeviceLink/SDLShowResponse.m
index 40912b163..75a5819aa 100644
--- a/SmartDeviceLink/SDLShowResponse.m
+++ b/SmartDeviceLink/SDLShowResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLShowResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSliderResponse.h b/SmartDeviceLink/SDLSliderResponse.h
index f31a74a6e..f6dc234ac 100644
--- a/SmartDeviceLink/SDLSliderResponse.h
+++ b/SmartDeviceLink/SDLSliderResponse.h
@@ -9,11 +9,16 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSliderResponse : SDLRPCResponse
 
 /**
  * @abstract The selected position of the slider.
  */
-@property (strong) NSNumber<SDLInt> *sliderPosition;
+@property (nullable, strong) NSNumber<SDLInt> *sliderPosition;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSliderResponse.m b/SmartDeviceLink/SDLSliderResponse.m
index 9d5872393..aa53544d7 100644
--- a/SmartDeviceLink/SDLSliderResponse.m
+++ b/SmartDeviceLink/SDLSliderResponse.m
@@ -14,7 +14,7 @@
     return self;
 }
 
-- (void)setSliderPosition:(NSNumber<SDLInt> *)sliderPosition {
+- (void)setSliderPosition:(nullable NSNumber<SDLInt> *)sliderPosition {
     if (sliderPosition != nil) {
         [parameters setObject:sliderPosition forKey:SDLNameSliderPosition];
     } else {
@@ -22,7 +22,7 @@
     }
 }
 
-- (NSNumber<SDLInt> *)sliderPosition {
+- (nullable NSNumber<SDLInt> *)sliderPosition {
     return [parameters objectForKey:SDLNameSliderPosition];
 }
 
diff --git a/SmartDeviceLink/SDLSpeakResponse.h b/SmartDeviceLink/SDLSpeakResponse.h
index c241e7d37..8e4c44261 100644
--- a/SmartDeviceLink/SDLSpeakResponse.h
+++ b/SmartDeviceLink/SDLSpeakResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSpeakResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSpeakResponse.m b/SmartDeviceLink/SDLSpeakResponse.m
index fd9899636..d61fa37a3 100644
--- a/SmartDeviceLink/SDLSpeakResponse.m
+++ b/SmartDeviceLink/SDLSpeakResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSpeakResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeButtonResponse.h b/SmartDeviceLink/SDLSubscribeButtonResponse.h
index bf9c22604..74a6fad0b 100644
--- a/SmartDeviceLink/SDLSubscribeButtonResponse.h
+++ b/SmartDeviceLink/SDLSubscribeButtonResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSubscribeButtonResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeButtonResponse.m b/SmartDeviceLink/SDLSubscribeButtonResponse.m
index 80a9b3a85..ca14f3861 100644
--- a/SmartDeviceLink/SDLSubscribeButtonResponse.m
+++ b/SmartDeviceLink/SDLSubscribeButtonResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSubscribeButtonResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeVehicleDataResponse.h b/SmartDeviceLink/SDLSubscribeVehicleDataResponse.h
index ca7d9917f..04da0a87c 100644
--- a/SmartDeviceLink/SDLSubscribeVehicleDataResponse.h
+++ b/SmartDeviceLink/SDLSubscribeVehicleDataResponse.h
@@ -11,106 +11,111 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSubscribeVehicleDataResponse : SDLRPCResponse
 
 /**
  * @abstract A SDLVehicleDataResult* value. See GPSData.
  */
-@property (strong) SDLVehicleDataResult *gps;
+@property (nullable, strong) SDLVehicleDataResult *gps;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The vehicle speed in kilometers per hour.
  */
-@property (strong) SDLVehicleDataResult *speed;
+@property (nullable, strong) SDLVehicleDataResult *speed;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The number of revolutions per minute of the engine.
  */
-@property (strong) SDLVehicleDataResult *rpm;
+@property (nullable, strong) SDLVehicleDataResult *rpm;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The fuel level in the tank (percentage)
  */
-@property (strong) SDLVehicleDataResult *fuelLevel;
+@property (nullable, strong) SDLVehicleDataResult *fuelLevel;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The fuel level state.
  */
-@property (strong) SDLVehicleDataResult *fuelLevel_State;
+@property (nullable, strong) SDLVehicleDataResult *fuelLevel_State;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The instantaneous fuel consumption in microlitres.
  */
-@property (strong) SDLVehicleDataResult *instantFuelConsumption;
+@property (nullable, strong) SDLVehicleDataResult *instantFuelConsumption;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The external temperature in degrees celsius.
  */
-@property (strong) SDLVehicleDataResult *externalTemperature;
+@property (nullable, strong) SDLVehicleDataResult *externalTemperature;
 
 /**
  * @abstract A SDLVehicleDataResult* value. See PRNDL.
  */
-@property (strong) SDLVehicleDataResult *prndl;
+@property (nullable, strong) SDLVehicleDataResult *prndl;
 
 /**
  * @abstract A SDLVehicleDataResult* value. See TireStatus.
  */
-@property (strong) SDLVehicleDataResult *tirePressure;
+@property (nullable, strong) SDLVehicleDataResult *tirePressure;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Odometer in km.
  */
-@property (strong) SDLVehicleDataResult *odometer;
+@property (nullable, strong) SDLVehicleDataResult *odometer;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the seat belts.
  */
-@property (strong) SDLVehicleDataResult *beltStatus;
+@property (nullable, strong) SDLVehicleDataResult *beltStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The body information including power modes.
  */
-@property (strong) SDLVehicleDataResult *bodyInformation;
+@property (nullable, strong) SDLVehicleDataResult *bodyInformation;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The device status including signal and battery strength.
  */
-@property (strong) SDLVehicleDataResult *deviceStatus;
+@property (nullable, strong) SDLVehicleDataResult *deviceStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the brake pedal.
  */
-@property (strong) SDLVehicleDataResult *driverBraking;
+@property (nullable, strong) SDLVehicleDataResult *driverBraking;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the wipers.
  */
-@property (strong) SDLVehicleDataResult *wiperStatus;
+@property (nullable, strong) SDLVehicleDataResult *wiperStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Status of the head lamps.
  */
-@property (strong) SDLVehicleDataResult *headLampStatus;
+@property (nullable, strong) SDLVehicleDataResult *headLampStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Torque value for engine (in Nm) on non-diesel variants.
  */
-@property (strong) SDLVehicleDataResult *engineTorque;
+@property (nullable, strong) SDLVehicleDataResult *engineTorque;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Accelerator pedal position (percentage depressed)
  */
-@property (strong) SDLVehicleDataResult *accPedalPosition;
+@property (nullable, strong) SDLVehicleDataResult *accPedalPosition;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Current angle of the steering wheel (in deg)
  */
-@property (strong) SDLVehicleDataResult *steeringWheelAngle;
-@property (strong) SDLVehicleDataResult *eCallInfo;
-@property (strong) SDLVehicleDataResult *airbagStatus;
-@property (strong) SDLVehicleDataResult *emergencyEvent;
-@property (strong) SDLVehicleDataResult *clusterModes;
-@property (strong) SDLVehicleDataResult *myKey;
+@property (nullable, strong) SDLVehicleDataResult *steeringWheelAngle;
+@property (nullable, strong) SDLVehicleDataResult *eCallInfo;
+@property (nullable, strong) SDLVehicleDataResult *airbagStatus;
+@property (nullable, strong) SDLVehicleDataResult *emergencyEvent;
+@property (nullable, strong) SDLVehicleDataResult *clusterModes;
+@property (nullable, strong) SDLVehicleDataResult *myKey;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeVehicleDataResponse.m b/SmartDeviceLink/SDLSubscribeVehicleDataResponse.m
index c251fb60f..194c7c706 100644
--- a/SmartDeviceLink/SDLSubscribeVehicleDataResponse.m
+++ b/SmartDeviceLink/SDLSubscribeVehicleDataResponse.m
@@ -7,6 +7,8 @@
 #import "SDLNames.h"
 #import "SDLVehicleDataResult.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSubscribeVehicleDataResponse
 
 - (instancetype)init {
@@ -15,7 +17,7 @@
     return self;
 }
 
-- (void)setGps:(SDLVehicleDataResult *)gps {
+- (void)setGps:(nullable SDLVehicleDataResult *)gps {
     if (gps != nil) {
         [parameters setObject:gps forKey:SDLNameGPS];
     } else {
@@ -23,7 +25,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)gps {
+- (nullable SDLVehicleDataResult *)gps {
     NSObject *obj = [parameters objectForKey:SDLNameGPS];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -32,7 +34,7 @@
     }
 }
 
-- (void)setSpeed:(SDLVehicleDataResult *)speed {
+- (void)setSpeed:(nullable SDLVehicleDataResult *)speed {
     if (speed != nil) {
         [parameters setObject:speed forKey:SDLNameSpeed];
     } else {
@@ -40,7 +42,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)speed {
+- (nullable SDLVehicleDataResult *)speed {
     NSObject *obj = [parameters objectForKey:SDLNameSpeed];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -49,7 +51,7 @@
     }
 }
 
-- (void)setRpm:(SDLVehicleDataResult *)rpm {
+- (void)setRpm:(nullable SDLVehicleDataResult *)rpm {
     if (rpm != nil) {
         [parameters setObject:rpm forKey:SDLNameRPM];
     } else {
@@ -57,7 +59,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)rpm {
+- (nullable SDLVehicleDataResult *)rpm {
     NSObject *obj = [parameters objectForKey:SDLNameRPM];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -66,7 +68,7 @@
     }
 }
 
-- (void)setFuelLevel:(SDLVehicleDataResult *)fuelLevel {
+- (void)setFuelLevel:(nullable SDLVehicleDataResult *)fuelLevel {
     if (fuelLevel != nil) {
         [parameters setObject:fuelLevel forKey:SDLNameFuelLevel];
     } else {
@@ -74,7 +76,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)fuelLevel {
+- (nullable SDLVehicleDataResult *)fuelLevel {
     NSObject *obj = [parameters objectForKey:SDLNameFuelLevel];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -83,7 +85,7 @@
     }
 }
 
-- (void)setFuelLevel_State:(SDLVehicleDataResult *)fuelLevel_State {
+- (void)setFuelLevel_State:(nullable SDLVehicleDataResult *)fuelLevel_State {
     if (fuelLevel_State != nil) {
         [parameters setObject:fuelLevel_State forKey:SDLNameFuelLevelState];
     } else {
@@ -91,7 +93,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)fuelLevel_State {
+- (nullable SDLVehicleDataResult *)fuelLevel_State {
     NSObject *obj = [parameters objectForKey:SDLNameFuelLevelState];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -100,7 +102,7 @@
     }
 }
 
-- (void)setInstantFuelConsumption:(SDLVehicleDataResult *)instantFuelConsumption {
+- (void)setInstantFuelConsumption:(nullable SDLVehicleDataResult *)instantFuelConsumption {
     if (instantFuelConsumption != nil) {
         [parameters setObject:instantFuelConsumption forKey:SDLNameInstantFuelConsumption];
     } else {
@@ -108,7 +110,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)instantFuelConsumption {
+- (nullable SDLVehicleDataResult *)instantFuelConsumption {
     NSObject *obj = [parameters objectForKey:SDLNameInstantFuelConsumption];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -117,7 +119,7 @@
     }
 }
 
-- (void)setExternalTemperature:(SDLVehicleDataResult *)externalTemperature {
+- (void)setExternalTemperature:(nullable SDLVehicleDataResult *)externalTemperature {
     if (externalTemperature != nil) {
         [parameters setObject:externalTemperature forKey:SDLNameExternalTemperature];
     } else {
@@ -125,7 +127,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)externalTemperature {
+- (nullable SDLVehicleDataResult *)externalTemperature {
     NSObject *obj = [parameters objectForKey:SDLNameExternalTemperature];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -134,7 +136,7 @@
     }
 }
 
-- (void)setPrndl:(SDLVehicleDataResult *)prndl {
+- (void)setPrndl:(nullable SDLVehicleDataResult *)prndl {
     if (prndl != nil) {
         [parameters setObject:prndl forKey:SDLNamePRNDL];
     } else {
@@ -142,7 +144,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)prndl {
+- (nullable SDLVehicleDataResult *)prndl {
     NSObject *obj = [parameters objectForKey:SDLNamePRNDL];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -151,7 +153,7 @@
     }
 }
 
-- (void)setTirePressure:(SDLVehicleDataResult *)tirePressure {
+- (void)setTirePressure:(nullable SDLVehicleDataResult *)tirePressure {
     if (tirePressure != nil) {
         [parameters setObject:tirePressure forKey:SDLNameTirePressure];
     } else {
@@ -159,7 +161,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)tirePressure {
+- (nullable SDLVehicleDataResult *)tirePressure {
     NSObject *obj = [parameters objectForKey:SDLNameTirePressure];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -168,7 +170,7 @@
     }
 }
 
-- (void)setOdometer:(SDLVehicleDataResult *)odometer {
+- (void)setOdometer:(nullable SDLVehicleDataResult *)odometer {
     if (odometer != nil) {
         [parameters setObject:odometer forKey:SDLNameOdometer];
     } else {
@@ -176,7 +178,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)odometer {
+- (nullable SDLVehicleDataResult *)odometer {
     NSObject *obj = [parameters objectForKey:SDLNameOdometer];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -185,7 +187,7 @@
     }
 }
 
-- (void)setBeltStatus:(SDLVehicleDataResult *)beltStatus {
+- (void)setBeltStatus:(nullable SDLVehicleDataResult *)beltStatus {
     if (beltStatus != nil) {
         [parameters setObject:beltStatus forKey:SDLNameBeltStatus];
     } else {
@@ -193,7 +195,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)beltStatus {
+- (nullable SDLVehicleDataResult *)beltStatus {
     NSObject *obj = [parameters objectForKey:SDLNameBeltStatus];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -202,7 +204,7 @@
     }
 }
 
-- (void)setBodyInformation:(SDLVehicleDataResult *)bodyInformation {
+- (void)setBodyInformation:(nullable SDLVehicleDataResult *)bodyInformation {
     if (bodyInformation != nil) {
         [parameters setObject:bodyInformation forKey:SDLNameBodyInformation];
     } else {
@@ -210,7 +212,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)bodyInformation {
+- (nullable SDLVehicleDataResult *)bodyInformation {
     NSObject *obj = [parameters objectForKey:SDLNameBodyInformation];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -219,7 +221,7 @@
     }
 }
 
-- (void)setDeviceStatus:(SDLVehicleDataResult *)deviceStatus {
+- (void)setDeviceStatus:(nullable SDLVehicleDataResult *)deviceStatus {
     if (deviceStatus != nil) {
         [parameters setObject:deviceStatus forKey:SDLNameDeviceStatus];
     } else {
@@ -227,7 +229,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)deviceStatus {
+- (nullable SDLVehicleDataResult *)deviceStatus {
     NSObject *obj = [parameters objectForKey:SDLNameDeviceStatus];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -236,7 +238,7 @@
     }
 }
 
-- (void)setDriverBraking:(SDLVehicleDataResult *)driverBraking {
+- (void)setDriverBraking:(nullable SDLVehicleDataResult *)driverBraking {
     if (driverBraking != nil) {
         [parameters setObject:driverBraking forKey:SDLNameDriverBraking];
     } else {
@@ -244,7 +246,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)driverBraking {
+- (nullable SDLVehicleDataResult *)driverBraking {
     NSObject *obj = [parameters objectForKey:SDLNameDriverBraking];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -253,7 +255,7 @@
     }
 }
 
-- (void)setWiperStatus:(SDLVehicleDataResult *)wiperStatus {
+- (void)setWiperStatus:(nullable SDLVehicleDataResult *)wiperStatus {
     if (wiperStatus != nil) {
         [parameters setObject:wiperStatus forKey:SDLNameWiperStatus];
     } else {
@@ -261,7 +263,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)wiperStatus {
+- (nullable SDLVehicleDataResult *)wiperStatus {
     NSObject *obj = [parameters objectForKey:SDLNameWiperStatus];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -270,7 +272,7 @@
     }
 }
 
-- (void)setHeadLampStatus:(SDLVehicleDataResult *)headLampStatus {
+- (void)setHeadLampStatus:(nullable SDLVehicleDataResult *)headLampStatus {
     if (headLampStatus != nil) {
         [parameters setObject:headLampStatus forKey:SDLNameHeadLampStatus];
     } else {
@@ -278,7 +280,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)headLampStatus {
+- (nullable SDLVehicleDataResult *)headLampStatus {
     NSObject *obj = [parameters objectForKey:SDLNameHeadLampStatus];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -287,7 +289,7 @@
     }
 }
 
-- (void)setEngineTorque:(SDLVehicleDataResult *)engineTorque {
+- (void)setEngineTorque:(nullable SDLVehicleDataResult *)engineTorque {
     if (engineTorque != nil) {
         [parameters setObject:engineTorque forKey:SDLNameEngineTorque];
     } else {
@@ -295,7 +297,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)engineTorque {
+- (nullable SDLVehicleDataResult *)engineTorque {
     NSObject *obj = [parameters objectForKey:SDLNameEngineTorque];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -304,7 +306,7 @@
     }
 }
 
-- (void)setAccPedalPosition:(SDLVehicleDataResult *)accPedalPosition {
+- (void)setAccPedalPosition:(nullable SDLVehicleDataResult *)accPedalPosition {
     if (accPedalPosition != nil) {
         [parameters setObject:accPedalPosition forKey:SDLNameAccelerationPedalPosition];
     } else {
@@ -312,7 +314,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)accPedalPosition {
+- (nullable SDLVehicleDataResult *)accPedalPosition {
     NSObject *obj = [parameters objectForKey:SDLNameAccelerationPedalPosition];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -321,7 +323,7 @@
     }
 }
 
-- (void)setSteeringWheelAngle:(SDLVehicleDataResult *)steeringWheelAngle {
+- (void)setSteeringWheelAngle:(nullable SDLVehicleDataResult *)steeringWheelAngle {
     if (steeringWheelAngle != nil) {
         [parameters setObject:steeringWheelAngle forKey:SDLNameSteeringWheelAngle];
     } else {
@@ -329,7 +331,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)steeringWheelAngle {
+- (nullable SDLVehicleDataResult *)steeringWheelAngle {
     NSObject *obj = [parameters objectForKey:SDLNameSteeringWheelAngle];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -338,7 +340,7 @@
     }
 }
 
-- (void)setECallInfo:(SDLVehicleDataResult *)eCallInfo {
+- (void)setECallInfo:(nullable SDLVehicleDataResult *)eCallInfo {
     if (eCallInfo != nil) {
         [parameters setObject:eCallInfo forKey:SDLNameECallInfo];
     } else {
@@ -346,7 +348,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)eCallInfo {
+- (nullable SDLVehicleDataResult *)eCallInfo {
     NSObject *obj = [parameters objectForKey:SDLNameECallInfo];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -355,7 +357,7 @@
     }
 }
 
-- (void)setAirbagStatus:(SDLVehicleDataResult *)airbagStatus {
+- (void)setAirbagStatus:(nullable SDLVehicleDataResult *)airbagStatus {
     if (airbagStatus != nil) {
         [parameters setObject:airbagStatus forKey:SDLNameAirbagStatus];
     } else {
@@ -363,7 +365,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)airbagStatus {
+- (nullable SDLVehicleDataResult *)airbagStatus {
     NSObject *obj = [parameters objectForKey:SDLNameAirbagStatus];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -372,7 +374,7 @@
     }
 }
 
-- (void)setEmergencyEvent:(SDLVehicleDataResult *)emergencyEvent {
+- (void)setEmergencyEvent:(nullable SDLVehicleDataResult *)emergencyEvent {
     if (emergencyEvent != nil) {
         [parameters setObject:emergencyEvent forKey:SDLNameEmergencyEvent];
     } else {
@@ -380,7 +382,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)emergencyEvent {
+- (nullable SDLVehicleDataResult *)emergencyEvent {
     NSObject *obj = [parameters objectForKey:SDLNameEmergencyEvent];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -389,7 +391,7 @@
     }
 }
 
-- (void)setClusterModes:(SDLVehicleDataResult *)clusterModes {
+- (void)setClusterModes:(nullable SDLVehicleDataResult *)clusterModes {
     if (clusterModes != nil) {
         [parameters setObject:clusterModes forKey:SDLNameClusterModes];
     } else {
@@ -397,7 +399,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)clusterModes {
+- (nullable SDLVehicleDataResult *)clusterModes {
     NSObject *obj = [parameters objectForKey:SDLNameClusterModes];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -406,7 +408,7 @@
     }
 }
 
-- (void)setMyKey:(SDLVehicleDataResult *)myKey {
+- (void)setMyKey:(nullable SDLVehicleDataResult *)myKey {
     if (myKey != nil) {
         [parameters setObject:myKey forKey:SDLNameMyKey];
     } else {
@@ -414,7 +416,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)myKey {
+- (nullable SDLVehicleDataResult *)myKey {
     NSObject *obj = [parameters objectForKey:SDLNameMyKey];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -424,3 +426,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeWaypointsResponse.h b/SmartDeviceLink/SDLSubscribeWaypointsResponse.h
index 9d4cfd967..8e8cf64f6 100644
--- a/SmartDeviceLink/SDLSubscribeWaypointsResponse.h
+++ b/SmartDeviceLink/SDLSubscribeWaypointsResponse.h
@@ -3,6 +3,10 @@
 
 #import "SDLRPCResponse.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSubscribeWaypointsResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSyncPDataResponse.h b/SmartDeviceLink/SDLSyncPDataResponse.h
index be1905ba1..ae3034a46 100644
--- a/SmartDeviceLink/SDLSyncPDataResponse.h
+++ b/SmartDeviceLink/SDLSyncPDataResponse.h
@@ -4,6 +4,10 @@
 
 #import "SDLRPCResponse.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSyncPDataResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSyncPDataResponse.m b/SmartDeviceLink/SDLSyncPDataResponse.m
index 95dbbf905..f6faea873 100644
--- a/SmartDeviceLink/SDLSyncPDataResponse.m
+++ b/SmartDeviceLink/SDLSyncPDataResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSyncPDataResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSystemRequestResponse.h b/SmartDeviceLink/SDLSystemRequestResponse.h
index 805962d3c..306ad48ea 100644
--- a/SmartDeviceLink/SDLSystemRequestResponse.h
+++ b/SmartDeviceLink/SDLSystemRequestResponse.h
@@ -7,6 +7,11 @@
 /** SDLSystemRequestResponse is sent, when SDLSystemRequest has been called.
  * Since<b>SmartDeviceLink 3.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSystemRequestResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSystemRequestResponse.m b/SmartDeviceLink/SDLSystemRequestResponse.m
index 8d12fe6a8..25154c3ab 100644
--- a/SmartDeviceLink/SDLSystemRequestResponse.m
+++ b/SmartDeviceLink/SDLSystemRequestResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSystemRequestResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.h b/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.h
index 1c6420f8e..c7088fc3e 100644
--- a/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.h
+++ b/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.h
@@ -9,6 +9,11 @@
  *
  * @since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnregisterAppInterfaceResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.m b/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.m
index ca1b8953c..dcc9d39bf 100644
--- a/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.m
+++ b/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnregisterAppInterfaceResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeButtonResponse.h b/SmartDeviceLink/SDLUnsubscribeButtonResponse.h
index 8dc43fad7..941cea512 100644
--- a/SmartDeviceLink/SDLUnsubscribeButtonResponse.h
+++ b/SmartDeviceLink/SDLUnsubscribeButtonResponse.h
@@ -9,6 +9,11 @@
  *
  * @since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnsubscribeButtonResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeButtonResponse.m b/SmartDeviceLink/SDLUnsubscribeButtonResponse.m
index 2f45d790e..d85f149cb 100644
--- a/SmartDeviceLink/SDLUnsubscribeButtonResponse.m
+++ b/SmartDeviceLink/SDLUnsubscribeButtonResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnsubscribeButtonResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.h b/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.h
index eecce7b75..90e6ec480 100644
--- a/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.h
+++ b/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.h
@@ -11,106 +11,111 @@
  *
  * @since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnsubscribeVehicleDataResponse : SDLRPCResponse
 
 /**
  * @abstract A SDLVehicleDataResult* value. See GPSData.
  */
-@property (strong) SDLVehicleDataResult *gps;
+@property (nullable, strong) SDLVehicleDataResult *gps;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The vehicle speed in kilometers per hour.
  */
-@property (strong) SDLVehicleDataResult *speed;
+@property (nullable, strong) SDLVehicleDataResult *speed;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The number of revolutions per minute of the engine.
  */
-@property (strong) SDLVehicleDataResult *rpm;
+@property (nullable, strong) SDLVehicleDataResult *rpm;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The fuel level in the tank (percentage)
  */
-@property (strong) SDLVehicleDataResult *fuelLevel;
+@property (nullable, strong) SDLVehicleDataResult *fuelLevel;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The fuel level state.
  */
-@property (strong) SDLVehicleDataResult *fuelLevel_State;
+@property (nullable, strong) SDLVehicleDataResult *fuelLevel_State;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The instantaneous fuel consumption in microlitres.
  */
-@property (strong) SDLVehicleDataResult *instantFuelConsumption;
+@property (nullable, strong) SDLVehicleDataResult *instantFuelConsumption;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The external temperature in degrees celsius.
  */
-@property (strong) SDLVehicleDataResult *externalTemperature;
+@property (nullable, strong) SDLVehicleDataResult *externalTemperature;
 
 /**
  * @abstract A SDLVehicleDataResult* value. See PRNDL.
  */
-@property (strong) SDLVehicleDataResult *prndl;
+@property (nullable, strong) SDLVehicleDataResult *prndl;
 
 /**
  * @abstract A SDLVehicleDataResult* value. See TireStatus.
  */
-@property (strong) SDLVehicleDataResult *tirePressure;
+@property (nullable, strong) SDLVehicleDataResult *tirePressure;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Odometer in km.
  */
-@property (strong) SDLVehicleDataResult *odometer;
+@property (nullable, strong) SDLVehicleDataResult *odometer;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the seat belts.
  */
-@property (strong) SDLVehicleDataResult *beltStatus;
+@property (nullable, strong) SDLVehicleDataResult *beltStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The body information including power modes.
  */
-@property (strong) SDLVehicleDataResult *bodyInformation;
+@property (nullable, strong) SDLVehicleDataResult *bodyInformation;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The device status including signal and battery strength.
  */
-@property (strong) SDLVehicleDataResult *deviceStatus;
+@property (nullable, strong) SDLVehicleDataResult *deviceStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the brake pedal.
  */
-@property (strong) SDLVehicleDataResult *driverBraking;
+@property (nullable, strong) SDLVehicleDataResult *driverBraking;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the wipers.
  */
-@property (strong) SDLVehicleDataResult *wiperStatus;
+@property (nullable, strong) SDLVehicleDataResult *wiperStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Status of the head lamps.
  */
-@property (strong) SDLVehicleDataResult *headLampStatus;
+@property (nullable, strong) SDLVehicleDataResult *headLampStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Torque value for engine (in Nm) on non-diesel variants.
  */
-@property (strong) SDLVehicleDataResult *engineTorque;
+@property (nullable, strong) SDLVehicleDataResult *engineTorque;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Accelerator pedal position (percentage depressed)
  */
-@property (strong) SDLVehicleDataResult *accPedalPosition;
+@property (nullable, strong) SDLVehicleDataResult *accPedalPosition;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Current angle of the steering wheel (in deg)
  */
-@property (strong) SDLVehicleDataResult *steeringWheelAngle;
-@property (strong) SDLVehicleDataResult *eCallInfo;
-@property (strong) SDLVehicleDataResult *airbagStatus;
-@property (strong) SDLVehicleDataResult *emergencyEvent;
-@property (strong) SDLVehicleDataResult *clusterModes;
-@property (strong) SDLVehicleDataResult *myKey;
+@property (nullable, strong) SDLVehicleDataResult *steeringWheelAngle;
+@property (nullable, strong) SDLVehicleDataResult *eCallInfo;
+@property (nullable, strong) SDLVehicleDataResult *airbagStatus;
+@property (nullable, strong) SDLVehicleDataResult *emergencyEvent;
+@property (nullable, strong) SDLVehicleDataResult *clusterModes;
+@property (nullable, strong) SDLVehicleDataResult *myKey;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.m b/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.m
index 5fd117563..36691e5e4 100644
--- a/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.m
+++ b/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.m
@@ -15,7 +15,7 @@
     return self;
 }
 
-- (void)setGps:(SDLVehicleDataResult *)gps {
+- (void)setGps:(nullable SDLVehicleDataResult *)gps {
     if (gps != nil) {
         [parameters setObject:gps forKey:SDLNameGPS];
     } else {
@@ -23,7 +23,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)gps {
+- (nullable SDLVehicleDataResult *)gps {
     NSObject *obj = [parameters objectForKey:SDLNameGPS];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -32,7 +32,7 @@
     }
 }
 
-- (void)setSpeed:(SDLVehicleDataResult *)speed {
+- (void)setSpeed:(nullable SDLVehicleDataResult *)speed {
     if (speed != nil) {
         [parameters setObject:speed forKey:SDLNameSpeed];
     } else {
@@ -40,7 +40,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)speed {
+- (nullable SDLVehicleDataResult *)speed {
     NSObject *obj = [parameters objectForKey:SDLNameSpeed];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -49,7 +49,7 @@
     }
 }
 
-- (void)setRpm:(SDLVehicleDataResult *)rpm {
+- (void)setRpm:(nullable SDLVehicleDataResult *)rpm {
     if (rpm != nil) {
         [parameters setObject:rpm forKey:SDLNameRPM];
     } else {
@@ -57,7 +57,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)rpm {
+- (nullable SDLVehicleDataResult *)rpm {
     NSObject *obj = [parameters objectForKey:SDLNameRPM];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -66,7 +66,7 @@
     }
 }
 
-- (void)setFuelLevel:(SDLVehicleDataResult *)fuelLevel {
+- (void)setFuelLevel:(nullable SDLVehicleDataResult *)fuelLevel {
     if (fuelLevel != nil) {
         [parameters setObject:fuelLevel forKey:SDLNameFuelLevel];
     } else {
@@ -74,7 +74,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)fuelLevel {
+- (nullable SDLVehicleDataResult *)fuelLevel {
     NSObject *obj = [parameters objectForKey:SDLNameFuelLevel];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -83,7 +83,7 @@
     }
 }
 
-- (void)setFuelLevel_State:(SDLVehicleDataResult *)fuelLevel_State {
+- (void)setFuelLevel_State:(nullable SDLVehicleDataResult *)fuelLevel_State {
     if (fuelLevel_State != nil) {
         [parameters setObject:fuelLevel_State forKey:SDLNameFuelLevelState];
     } else {
@@ -91,7 +91,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)fuelLevel_State {
+- (nullable SDLVehicleDataResult *)fuelLevel_State {
     NSObject *obj = [parameters objectForKey:SDLNameFuelLevelState];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -100,7 +100,7 @@
     }
 }
 
-- (void)setInstantFuelConsumption:(SDLVehicleDataResult *)instantFuelConsumption {
+- (void)setInstantFuelConsumption:(nullable SDLVehicleDataResult *)instantFuelConsumption {
     if (instantFuelConsumption != nil) {
         [parameters setObject:instantFuelConsumption forKey:SDLNameInstantFuelConsumption];
     } else {
@@ -108,7 +108,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)instantFuelConsumption {
+- (nullable SDLVehicleDataResult *)instantFuelConsumption {
     NSObject *obj = [parameters objectForKey:SDLNameInstantFuelConsumption];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -117,7 +117,7 @@
     }
 }
 
-- (void)setExternalTemperature:(SDLVehicleDataResult *)externalTemperature {
+- (void)setExternalTemperature:(nullable SDLVehicleDataResult *)externalTemperature {
     if (externalTemperature != nil) {
         [parameters setObject:externalTemperature forKey:SDLNameExternalTemperature];
     } else {
@@ -125,7 +125,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)externalTemperature {
+- (nullable SDLVehicleDataResult *)externalTemperature {
     NSObject *obj = [parameters objectForKey:SDLNameExternalTemperature];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -134,7 +134,7 @@
     }
 }
 
-- (void)setPrndl:(SDLVehicleDataResult *)prndl {
+- (void)setPrndl:(nullable SDLVehicleDataResult *)prndl {
     if (prndl != nil) {
         [parameters setObject:prndl forKey:SDLNamePRNDL];
     } else {
@@ -142,7 +142,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)prndl {
+- (nullable SDLVehicleDataResult *)prndl {
     NSObject *obj = [parameters objectForKey:SDLNamePRNDL];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -151,7 +151,7 @@
     }
 }
 
-- (void)setTirePressure:(SDLVehicleDataResult *)tirePressure {
+- (void)setTirePressure:(nullable SDLVehicleDataResult *)tirePressure {
     if (tirePressure != nil) {
         [parameters setObject:tirePressure forKey:SDLNameTirePressure];
     } else {
@@ -159,7 +159,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)tirePressure {
+- (nullable SDLVehicleDataResult *)tirePressure {
     NSObject *obj = [parameters objectForKey:SDLNameTirePressure];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -168,7 +168,7 @@
     }
 }
 
-- (void)setOdometer:(SDLVehicleDataResult *)odometer {
+- (void)setOdometer:(nullable SDLVehicleDataResult *)odometer {
     if (odometer != nil) {
         [parameters setObject:odometer forKey:SDLNameOdometer];
     } else {
@@ -176,7 +176,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)odometer {
+- (nullable SDLVehicleDataResult *)odometer {
     NSObject *obj = [parameters objectForKey:SDLNameOdometer];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -185,7 +185,7 @@
     }
 }
 
-- (void)setBeltStatus:(SDLVehicleDataResult *)beltStatus {
+- (void)setBeltStatus:(nullable SDLVehicleDataResult *)beltStatus {
     if (beltStatus != nil) {
         [parameters setObject:beltStatus forKey:SDLNameBeltStatus];
     } else {
@@ -193,7 +193,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)beltStatus {
+- (nullable SDLVehicleDataResult *)beltStatus {
     NSObject *obj = [parameters objectForKey:SDLNameBeltStatus];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -202,7 +202,7 @@
     }
 }
 
-- (void)setBodyInformation:(SDLVehicleDataResult *)bodyInformation {
+- (void)setBodyInformation:(nullable SDLVehicleDataResult *)bodyInformation {
     if (bodyInformation != nil) {
         [parameters setObject:bodyInformation forKey:SDLNameBodyInformation];
     } else {
@@ -210,7 +210,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)bodyInformation {
+- (nullable SDLVehicleDataResult *)bodyInformation {
     NSObject *obj = [parameters objectForKey:SDLNameBodyInformation];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -219,7 +219,7 @@
     }
 }
 
-- (void)setDeviceStatus:(SDLVehicleDataResult *)deviceStatus {
+- (void)setDeviceStatus:(nullable SDLVehicleDataResult *)deviceStatus {
     if (deviceStatus != nil) {
         [parameters setObject:deviceStatus forKey:SDLNameDeviceStatus];
     } else {
@@ -227,7 +227,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)deviceStatus {
+- (nullable SDLVehicleDataResult *)deviceStatus {
     NSObject *obj = [parameters objectForKey:SDLNameDeviceStatus];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -236,7 +236,7 @@
     }
 }
 
-- (void)setDriverBraking:(SDLVehicleDataResult *)driverBraking {
+- (void)setDriverBraking:(nullable SDLVehicleDataResult *)driverBraking {
     if (driverBraking != nil) {
         [parameters setObject:driverBraking forKey:SDLNameDriverBraking];
     } else {
@@ -244,7 +244,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)driverBraking {
+- (nullable SDLVehicleDataResult *)driverBraking {
     NSObject *obj = [parameters objectForKey:SDLNameDriverBraking];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -253,7 +253,7 @@
     }
 }
 
-- (void)setWiperStatus:(SDLVehicleDataResult *)wiperStatus {
+- (void)setWiperStatus:(nullable SDLVehicleDataResult *)wiperStatus {
     if (wiperStatus != nil) {
         [parameters setObject:wiperStatus forKey:SDLNameWiperStatus];
     } else {
@@ -261,7 +261,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)wiperStatus {
+- (nullable SDLVehicleDataResult *)wiperStatus {
     NSObject *obj = [parameters objectForKey:SDLNameWiperStatus];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -270,7 +270,7 @@
     }
 }
 
-- (void)setHeadLampStatus:(SDLVehicleDataResult *)headLampStatus {
+- (void)setHeadLampStatus:(nullable SDLVehicleDataResult *)headLampStatus {
     if (headLampStatus != nil) {
         [parameters setObject:headLampStatus forKey:SDLNameHeadLampStatus];
     } else {
@@ -278,7 +278,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)headLampStatus {
+- (nullable SDLVehicleDataResult *)headLampStatus {
     NSObject *obj = [parameters objectForKey:SDLNameHeadLampStatus];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -287,7 +287,7 @@
     }
 }
 
-- (void)setEngineTorque:(SDLVehicleDataResult *)engineTorque {
+- (void)setEngineTorque:(nullable SDLVehicleDataResult *)engineTorque {
     if (engineTorque != nil) {
         [parameters setObject:engineTorque forKey:SDLNameEngineTorque];
     } else {
@@ -295,7 +295,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)engineTorque {
+- (nullable SDLVehicleDataResult *)engineTorque {
     NSObject *obj = [parameters objectForKey:SDLNameEngineTorque];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -304,7 +304,7 @@
     }
 }
 
-- (void)setAccPedalPosition:(SDLVehicleDataResult *)accPedalPosition {
+- (void)setAccPedalPosition:(nullable SDLVehicleDataResult *)accPedalPosition {
     if (accPedalPosition != nil) {
         [parameters setObject:accPedalPosition forKey:SDLNameAccelerationPedalPosition];
     } else {
@@ -312,7 +312,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)accPedalPosition {
+- (nullable SDLVehicleDataResult *)accPedalPosition {
     NSObject *obj = [parameters objectForKey:SDLNameAccelerationPedalPosition];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -321,7 +321,7 @@
     }
 }
 
-- (void)setSteeringWheelAngle:(SDLVehicleDataResult *)steeringWheelAngle {
+- (void)setSteeringWheelAngle:(nullable SDLVehicleDataResult *)steeringWheelAngle {
     if (steeringWheelAngle != nil) {
         [parameters setObject:steeringWheelAngle forKey:SDLNameSteeringWheelAngle];
     } else {
@@ -329,7 +329,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)steeringWheelAngle {
+- (nullable SDLVehicleDataResult *)steeringWheelAngle {
     NSObject *obj = [parameters objectForKey:SDLNameSteeringWheelAngle];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -338,7 +338,7 @@
     }
 }
 
-- (void)setECallInfo:(SDLVehicleDataResult *)eCallInfo {
+- (void)setECallInfo:(nullable SDLVehicleDataResult *)eCallInfo {
     if (eCallInfo != nil) {
         [parameters setObject:eCallInfo forKey:SDLNameECallInfo];
     } else {
@@ -346,7 +346,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)eCallInfo {
+- (nullable SDLVehicleDataResult *)eCallInfo {
     NSObject *obj = [parameters objectForKey:SDLNameECallInfo];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -355,7 +355,7 @@
     }
 }
 
-- (void)setAirbagStatus:(SDLVehicleDataResult *)airbagStatus {
+- (void)setAirbagStatus:(nullable SDLVehicleDataResult *)airbagStatus {
     if (airbagStatus != nil) {
         [parameters setObject:airbagStatus forKey:SDLNameAirbagStatus];
     } else {
@@ -363,7 +363,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)airbagStatus {
+- (nullable SDLVehicleDataResult *)airbagStatus {
     NSObject *obj = [parameters objectForKey:SDLNameAirbagStatus];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -372,7 +372,7 @@
     }
 }
 
-- (void)setEmergencyEvent:(SDLVehicleDataResult *)emergencyEvent {
+- (void)setEmergencyEvent:(nullable SDLVehicleDataResult *)emergencyEvent {
     if (emergencyEvent != nil) {
         [parameters setObject:emergencyEvent forKey:SDLNameEmergencyEvent];
     } else {
@@ -380,7 +380,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)emergencyEvent {
+- (nullable SDLVehicleDataResult *)emergencyEvent {
     NSObject *obj = [parameters objectForKey:SDLNameEmergencyEvent];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -389,7 +389,7 @@
     }
 }
 
-- (void)setClusterModes:(SDLVehicleDataResult *)clusterModes {
+- (void)setClusterModes:(nullable SDLVehicleDataResult *)clusterModes {
     if (clusterModes != nil) {
         [parameters setObject:clusterModes forKey:SDLNameClusterModes];
     } else {
@@ -397,7 +397,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)clusterModes {
+- (nullable SDLVehicleDataResult *)clusterModes {
     NSObject *obj = [parameters objectForKey:SDLNameClusterModes];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
@@ -406,7 +406,7 @@
     }
 }
 
-- (void)setMyKey:(SDLVehicleDataResult *)myKey {
+- (void)setMyKey:(nullable SDLVehicleDataResult *)myKey {
     if (myKey != nil) {
         [parameters setObject:myKey forKey:SDLNameMyKey];
     } else {
@@ -414,7 +414,7 @@
     }
 }
 
-- (SDLVehicleDataResult *)myKey {
+- (nullable SDLVehicleDataResult *)myKey {
     NSObject *obj = [parameters objectForKey:SDLNameMyKey];
     if (obj == nil || [obj isKindOfClass:SDLVehicleDataResult.class]) {
         return (SDLVehicleDataResult *)obj;
diff --git a/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.h b/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.h
index e64cc2d73..b98d6d57a 100644
--- a/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.h
+++ b/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.h
@@ -3,6 +3,10 @@
 
 #import "SDLRPCResponse.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnsubscribeWaypointsResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.m b/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.m
index e0bdcbc30..c8d105e11 100644
--- a/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.m
+++ b/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.m
@@ -4,6 +4,8 @@
 #import "SDLUnsubscribeWaypointsResponse.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnsubscribeWaypointsResponse
 
 - (instancetype)init {
@@ -13,3 +15,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUpdateTurnListResponse.h b/SmartDeviceLink/SDLUpdateTurnListResponse.h
index ab2d87231..31ba28df5 100644
--- a/SmartDeviceLink/SDLUpdateTurnListResponse.h
+++ b/SmartDeviceLink/SDLUpdateTurnListResponse.h
@@ -7,6 +7,11 @@
 /** SDLUpdateTurnListResponse is sent, when SDLUpdateTurnList has been called.
  * Since<b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUpdateTurnListResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUpdateTurnListResponse.m b/SmartDeviceLink/SDLUpdateTurnListResponse.m
index 681e9c38c..95047fd66 100644
--- a/SmartDeviceLink/SDLUpdateTurnListResponse.m
+++ b/SmartDeviceLink/SDLUpdateTurnListResponse.m
@@ -6,6 +6,8 @@
 
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUpdateTurnListResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END