必要檔案
- rails/railtie
- rails/engine/railties
- active_support/callbacks
- active_support/core_ext/module/delegation
- active_support/core_ext/object/try
- pathname
- rake
- rails/generators
命名空間
- 模組 AbstractController
- 模組 ActionDispatch
- 模組 ActiveSupport
- 模組 Rails
- 類別 Rails::Engine