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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def process_event(self, event):
 """ Process a new input event. This method will pass the event on to any Effects in reverse Z order so that the top-most Effect has priority. :param event: The Event that has been triggered. :returns: None if the Scene processed the event, else the original event. """

        for effect in reversed(self._effects):
            event = effect.process_event(event)
            if event is None:
                break
        return event