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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 unregister(self, event):
 """ Remove all registered handlers for an event. Silent return when event was not registered. Usage: dispatch.unregister("my_event") dispatch.unregister("my_event") # no-op """

        if self.running:
            raise RuntimeError("Can't unregister while running")
        self._handlers.pop(event, None)