@utilities.remove_null_proxy_kwarg<EOL><INDENT>def get_proxy_session(self):<DEDENT>
if not self.supports_proxy():<EOL><INDENT>raise errors.Unimplemented()<EOL><DEDENT>return sessions.ProxySession(runtime=self._runtime)<EOL>
Gets a ``ProxySession`` which is responsible for acquiring authentication credentials on behalf of a service client.

        return: (osid.proxy.ProxySession) - a proxy session for this
                service
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented - ``supports_proxy()`` is ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_proxy()`` is ``true``.*