@abc.abstractmethod<EOL><INDENT>def has_agent(self):<DEDENT>
return<EOL>
Tests if this authorization has an ``Agent``.

        An implied authorization may have an ``Agent`` in addition to a
        specified ``Resource``.

        :return: ``true`` if this authorization has an ``Agent,``  ``false`` otherwise
        :rtype: ``boolean``


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