Definition files
- activesupport/lib/active_support/core_ext/object/json.rb
- activesupport/lib/active_support/event_reporter.rb
- activesupport/lib/active_support/file_update_checker.rb
- activesupport/lib/active_support/notifications/fanout.rb
- activesupport/lib/active_support/notifications/instrumenter.rb
- activesupport/lib/active_support/testing/parallelization.rb