def has_listener(self, event_type, listener):
        """
        Return true if listener is register to event_type
        """
        # Check for event type and for the listener
        if event_type in self._events.keys():
            return listener in self._events[ event_type ]
        else:
            return False

        Return true if listener is register to event_type
        
recipes/Python/577432_Simple_event_dispatcher/recipe-577432.py