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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 allocate_address(self):
 """ Acquire an elastic IP address to be attached subsequently to EC2 instances. @return: the IP address allocated. """

        # XXX remove empty other_params
        query = self.query_factory(
            action="AllocateAddress", creds=self.creds, endpoint=self.endpoint,
            other_params={})
        d = query.submit()
        return d.addCallback(self.parser.allocate_address)