Dispatch handling of this event to a receiver.

        This method will invoke ``receiver._document_model_dhanged`` if it
        exists.

def dispatch(self, receiver):
        ''' Dispatch handling of this event to a receiver.

        This method will invoke ``receiver._document_model_dhanged`` if it
        exists.

        '''
        super(ModelChangedEvent, self).dispatch(receiver)
        if hasattr(receiver, '_document_model_changed'):
            receiver._document_model_changed(self)