protected function message_write(Base $object, & $length=0)
    {
        Debug::Log(Debug::DEBUG, 'Message write: message_type='.Message::$name[$object->getMessageType()]);
        $length = 0;
        $message = $object->build($length);
        $bytes_written = $this->socket->write($message, $length);
        return $bytes_written;
    }