(self, topicName: str)
Called whenever a topic is removed from topic tree.
        :param topicName: name of topic removed.
Called whenever a topic is removed from topic tree.
        :param topicName: name of topic removed.
Called whenever a topic is removed from topic tree . : param topicName : name of topic removed .
def notifyDelTopic(self, topicName: str):
        """
        Called whenever a topic is removed from topic tree.
        :param topicName: name of topic removed.
        """
        raise NotImplementedError
def notifyDelTopic ( self , topicName : str ) : raise NotImplementedError