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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 remove(self, event, subscriber):
 """ Remove a subscriber for an event. :param event: The name of an event. :param subscriber: The subscriber to be removed. """

        subs = self._subscribers
        if event not in subs:
            raise ValueError('No subscribers: %r' % event)
        subs[event].remove(subscriber)