• active_support/core_ext/module/attribute_accessors
• active_support/syntax_error_proxy
• active_support/core_ext/thread/backtrace/location
• rack/utils

• 模块 ActionController
• 模块 ActionDispatch
• 模块 ActionView
• 模块 ActiveSupport
• 模块 Thread
• 类 ActionDispatch::ExceptionWrapper