@abc.abstractmethod<EOL><INDENT>def get_resource_id(self):<DEDENT>
return<EOL>
Gets the ``resource _id`` for this authorization.

        :return: the ``Resource Id``
        :rtype: ``osid.id.Id``
        :raise: ``IllegalState`` -- ``has_resource()`` is ``false``

        *compliance: mandatory -- This method must be implemented.*