replace `callback(null)` * 3 to `callback()` for consistency

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/async.js b/lib/async.js
index 4d460b3..c9f355f 100755
--- a/lib/async.js
+++ b/lib/async.js
@@ -123,7 +123,7 @@
           else {
               completed += 1;
               if (completed >= arr.length) {
-                  callback(null);
+                  callback();
               }
           }
         }
@@ -145,7 +145,7 @@
                 else {
                     completed += 1;
                     if (completed >= arr.length) {
-                        callback(null);
+                        callback();
                     }
                     else {
                         iterate();
@@ -404,7 +404,7 @@
         var keys = _keys(tasks);
         var remainingTasks = keys.length
         if (!remainingTasks) {
-            return callback(null);
+            return callback();
         }
 
         var results = {};