code: def register_watchers(self, type_callback_dict, register_timeout=None):
          
          for event_type, callback in type_callback_dict.items():
              self._push_watchers[event_type].add(callback)
          self.wait_for_response(
              RegisterMessage(event_list=type_callback_dict.keys()),
              timeout=register_timeout)
docs: Register multiple callback/event type pairs, expressed as a dict.