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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 unsubscribe(self, name):
 """Unsubscribe from a collection Arguments: name - the name of the publication"""

        self._wait_for_connect()
        if name not in self.subscriptions:
            raise MeteorClientException('No subscription for {}'.format(name))
        self.ddp_client.unsubscribe(self.subscriptions[name]['id'])
        del self.subscriptions[name]
        self.emit('unsubscribed', name)