code: function messageHandler() {
    var message = messages.read(arguments, _session.signer);
    if (!message) {
      return;
    }
  
    var handler = _session.handlers[message.header.msg_type];
    if (handler) {
      handler(message);
    }
  }
docs: The default message handler for both the Shell and Control sockets. This dispatches the message to the appropriate message handler, based on the type of the message.