code: def subscribe(self, handler: LutronEventHandler, context):
      
      self._subscribers.append((handler, context))
docs: Subscribes to events from this entity.
  
      handler: A callable object that takes the following arguments (in order)
               obj: the LutrongEntity object that generated the event
               context: user-supplied (to subscribe()) context object
               event: the LutronEvent that was generated.
               params: a dict of event-specific parameters
  
      context: User-supplied, opaque object that will be passed to handler.