def get_proxy_session(self, proxy):
raise Unimplemented()<EOL>
Gets the ``OsidSession`` associated with the ``ProxySession`` using the supplied ``Proxy``.

        :param proxy: proxy
        :type proxy: ``osid.proxy.Proxy``
        :return: a ``ProxySession``
        :rtype: ``osid.proxy.ProxySession``
        :raise: ``NullArgument`` -- ``proxy`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_proxy()`` is ``false``

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