(self)
Get the next topic definition available from the data. The return
        must be an instance of TopicDefn. Must return None when no topics
        are left.
Get the next topic definition available from the data. The return
        must be an instance of TopicDefn. Must return None when no topics
        are left.
Get the next topic definition available from the data . The return must be an instance of TopicDefn . Must return None when no topics are left .
def getNextTopic(self) -> 'TopicDefn':
        """
        Get the next topic definition available from the data. The return
        must be an instance of TopicDefn. Must return None when no topics
        are left.
        """
        raise NotImplementedError
def getNextTopic ( self ) -> 'TopicDefn' : raise NotImplementedError