1 files changed, 1 insertions, 18 deletions
diff --git a/app/models/resource_milestone_event.rb b/app/models/resource_milestone_event.rb
index 36068cf508b..5fd71612de0 100644
--- a/app/models/resource_milestone_event.rb
+++ b/app/models/resource_milestone_event.rb
@@ -1,30 +1,17 @@
 # frozen_string_literal: true
 
-class ResourceMilestoneEvent < ResourceEvent
+class ResourceMilestoneEvent < ResourceTimeboxEvent
   include IgnorableColumns
-  include IssueResourceEvent
-  include MergeRequestResourceEvent
 
   belongs_to :milestone
 
-  validate :exactly_one_issuable
-
   scope :include_relations, -> { includes(:user, milestone: [:project, :group]) }
 
-  enum action: {
-    add: 1,
-    remove: 2
-  }
-
   # state is used for issue and merge request states.
   enum state: Issue.available_states.merge(MergeRequest.available_states)
 
   ignore_columns %i[reference reference_html cached_markdown_version], remove_with: '13.1', remove_after: '2020-06-22'
 
-  def self.issuable_attrs
-    %i(issue merge_request).freeze
-  end
-
   def milestone_title
     milestone&.title
   end
@@ -32,8 +19,4 @@ class ResourceMilestoneEvent < ResourceEvent
   def milestone_parent
     milestone&.parent
   end
-
-  def issuable
-    issue || merge_request
-  end
 end