(self, event)
Abstract method to handle a `TopologyDescriptionChangedEvent`.

        :Parameters:
          - `event`: An instance of :class:`TopologyDescriptionChangedEvent`.
Abstract method to handle a `TopologyDescriptionChangedEvent`.
Abstract method to handle a TopologyDescriptionChangedEvent .
def description_changed(self, event):
        """Abstract method to handle a `TopologyDescriptionChangedEvent`.

        :Parameters:
          - `event`: An instance of :class:`TopologyDescriptionChangedEvent`.
        """
        raise NotImplementedError
def description_changed ( self , event ) : raise NotImplementedError