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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 create(self, callback_url):
 """Register a new Subscription on this collection's parent object. Args: callback_url (str):
 URI of an active endpoint which can receive notifications. Returns: A round.Subscription object if successful. """

        resource = self.resource.create({'subscribed_to': 'address',
                                         'callback_url': callback_url})
        subscription = self.wrap(resource)
        self.add(subscription)
        return subscription