ruby-on-rails - 受保护的 state_machines 事件

Question

我有一个模型，在状态列上有一个状态机，管理员和普通用户都可以更改。如何实施仅允许管理员触发特定事件的保护层？例如：

 state_machine :status, initial: :draft do

    # A user can change the status of his model to be reviewed
    event :review do
      transition draft: :in_review
    end

    # Only an admin can approve or disapprove
    event :approve do
      transition in_review: :approved
    end

    event :disapprove do
      transition in_review: :disapproved
    end
end

谢谢！