code: def _handle_msg_rcv(self, msg: "pb.Result") -> None:
      # deliver mailbox addressed messages to mailbox
      if self._mailbox and msg.control.mailbox_slot:
          self._mailbox.deliver(msg)
          return
      with self._lock:
          future = self._pending_reqs.pop(msg.uuid, None)
      if future is None:
          # TODO (cvp): saw this in tests, seemed benign enough to ignore, but
          # could point to other issues.
          if msg.uuid != "":
              tracelog.log_message_assert(msg)
              logger.warning(
                  "No listener found for msg with uuid %s (%s)",
                  msg.uuid,
                  msg,
              )
          return
      future._set_object(msg)
  
imports: import logging
  import threading
  import uuid
  from abc import abstractmethod
  from typing import TYPE_CHECKING, Dict, Optional
  from ..lib import mailbox, tracelog
  from .message_future import MessageFuture
label_desc: Use image node_id 7 for calling the MessageRouter obj's underlying member method code with example usage: obj._handle_msg_rcv(msg) without return types