code: def send_message_event(self, room_id, event_type, content, txn_id=None,
                             timestamp=None):
          
          if not txn_id:
              txn_id = self._make_txn_id()
  
          path = "/rooms/%s/send/%s/%s" % (
              quote(room_id), quote(event_type), quote(str(txn_id)),
          )
          params = {}
          if timestamp:
              params["ts"] = timestamp
          return self._send("PUT", path, content, query_params=params)
docs: Perform PUT /rooms/$room_id/send/$event_type
  
          Args:
              room_id (str): The room ID to send the message event in.
              event_type (str): The event type to send.
              content (dict): The JSON content to send.
              txn_id (int): Optional. The transaction ID to use.
              timestamp (int): Set origin_server_ts (For application services only)