Publish the message on the PUB socket with the given topic name.
        
        Args:
            - message: the message to publish
            - message_type: the type of message being sent
            - topic: the topic on which to send the message. Defaults to ''.

def publish(self,message,message_type,topic=''):
        """
        Publish the message on the PUB socket with the given topic name.
        
        Args:
            - message: the message to publish
            - message_type: the type of message being sent
            - topic: the topic on which to send the message. Defaults to ''.
        """
        if message_type == MULTIPART:
            raise Exception("Unsupported request type")

        super(Publisher,self).send(message,message_type,topic)