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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 get_listeners(self, event_type: str) -> List[Callable]: """Get all listeners of a particular type of event."""

        if event_type not in self.events:
            raise ValueError(f'No event {event_type} in system.')
        return self.events.get_listeners(event_type)