@abc.abstractmethod<EOL><INDENT>def get_authentication_keys_proxy_manager(self):<DEDENT>
return<EOL>
Gets an ``AuthenticationKeysProxyManager``.

        :return: an ``AuthenticationKeysProxyManager``.
        :rtype: ``osid.authentication.keys.AuthenticationKeysProxyManager``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_authentication_keys()`` is ``false``

        *compliance: optional -- This method must be implemented if
        ``supports_authentication_keys()`` is ``true``.*