code: def handle(client_message, handle_event_map_partition_lost=None, to_object=None):
      
      message_type = client_message.get_message_type()
      if message_type == EVENT_MAPPARTITIONLOST and handle_event_map_partition_lost is not None:
          partition_id = client_message.read_int()
          uuid = client_message.read_str()
          handle_event_map_partition_lost(partition_id=partition_id, uuid=uuid)
docs: Event handler