Just define allowed_ids and override it with empty value

if not needed for those sub-classes.

lib/gitlab/cycle_analytics/base_event_fetcher.rb

@@ -56,10 +56,6 @@ module Gitlab
       end
 
       def allowed_ids
-        nil
-      end
-
-      def load_allowed_ids
         allowed_ids_finder_class
           .new(@options[:current_user], project_id: @project.id)
           .execute.where(id: event_result_ids).pluck(:id)

lib/gitlab/cycle_analytics/code_event_fetcher.rb

@@ -19,10 +19,6 @@ module Gitlab
         AnalyticsMergeRequestSerializer.new(project: @project).represent(event)
       end
 
-      def allowed_ids
-        load_allowed_ids
-      end
-
       def allowed_ids_finder_class
         MergeRequestsFinder
       end

lib/gitlab/cycle_analytics/issue_event_fetcher.rb

@@ -17,10 +17,6 @@ module Gitlab
         AnalyticsIssueSerializer.new(project: @project).represent(event)
       end
 
-      def allowed_ids
-        load_allowed_ids
-      end
-
       def allowed_ids_finder_class
         IssuesFinder
       end

lib/gitlab/cycle_analytics/plan_event_fetcher.rb

@@ -19,6 +19,10 @@ module Gitlab
 
       private
 
+      def allowed_ids
+        nil
+      end
+
       def merge_request_diff_commits
         @merge_request_diff_commits ||=
           MergeRequestDiffCommit

lib/gitlab/cycle_analytics/review_event_fetcher.rb

@@ -18,10 +18,6 @@ module Gitlab
         AnalyticsMergeRequestSerializer.new(project: @project).represent(event)
       end
 
-      def allowed_ids
-        load_allowed_ids
-      end
-
       def allowed_ids_finder_class
         MergeRequestsFinder
       end

lib/gitlab/cycle_analytics/staging_event_fetcher.rb

@@ -22,6 +22,10 @@ module Gitlab
 
       private
 
+      def allowed_ids
+        nil
+      end
+
       def serialize(event)
         AnalyticsBuildSerializer.new.represent(event['build'])
       end

spec/lib/gitlab/cycle_analytics/base_event_fetcher_spec.rb

@@ -23,6 +23,8 @@ describe Gitlab::CycleAnalytics::BaseEventFetcher do
     allow_any_instance_of(described_class).to receive(:serialize) do |event|
       event
     end
+    allow_any_instance_of(described_class)
+      .to receive(:allowed_ids).and_return(nil)
 
     stub_const('Gitlab::CycleAnalytics::BaseEventFetcher::MAX_EVENTS', max_events)