    def process_event(self, event):
        """
        Process any input event.

        :param event: The event that was triggered.
        :returns: None if the Effect processed the event, else the original
                  event.
        """
        return event
Process any input event.

:param event: The event that was triggered.
:returns: None if the Effect processed the event, else the original
event.
asciimatics/effects.py