• active_support/core_ext/numeric/time
• active_job/continuable
• active_job/continuation/step

• MODULE ActiveJob
• 类 ActiveJob::Continuation
• 类 ActiveJob::Continuation::CheckpointError
• 类 ActiveJob::Continuation::Error
• 类 ActiveJob::Continuation::Interrupt
• 类 ActiveJob::Continuation::InvalidStepError
• 类 ActiveJob::Continuation::ResumeLimitError
• 类 ActiveJob::Continuation::UnadvanceableCursorError