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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 federation(self):
 """returns the class that controls federation"""

        url = self._url + "/federation"
        return _Federation(url=url,
                           securityHandler=self._securityHandler,
                           proxy_url=self._proxy_url,
                           proxy_port=self._proxy_port)