anchor.diff:      end),
   
       % when
  -    {ok, MsgId2} = rpc:call(Worker1, communicator, communicate_async,
  -        [ServerMsgInternal, SessionId]),
  +    {ok, MsgId2} = rpc:call(Worker1, communicator, communicate,
  +        [ServerMsgInternal, SessionId, #{use_msg_id => true}]),
   
       % then
       ?assertReceivedMatch({router_message_called, MsgId2}, ?TIMEOUT),
  
positive.code:     % when
      {ok, {Sock, SessionId}} = spawn_ssl_echo_client(Worker1),
      CommunicateResult = rpc:call(Worker1, communicator, communicate,
          [ServerMsgInternal, SessionId]),
  
      % then
      ?assertMatch({ok, #client_message{message_body = Status}}, CommunicateResult),
  
negative.code:     },
  
      % when
      ?assertEqual(ok, rpc:call(Worker1, communicator, send_to_client, 
          [ServerMsgInternal, SessionId])),
  
      % then
      ?assertEqual(ServerMessageProtobuf, fuse_utils:receive_server_message()),
  