What are the Responsibilities of MVCS Commands?
Commands are registered to a Context via that Context’s CommandMap. The CommandMap is available by default in Context and Command classes. Commands are registered to the Context with an Event type, the Command class to execute in response to the Event, and optionally the Event class and a one off setting for when a Command should be executed once, and then unregistered for future occurrences of an Event.
Reference MVCS Implementation