@abc.abstractmethod<EOL><INDENT>def supports_subject_relevancy_query(self):<DEDENT>
return<EOL>
Tests if a ``RelevancyQuery`` is available to provide queries about the relationships to ``Subjects``.

        :return: ``true`` if a relevancy entry query is available, ``false`` otherwise
        :rtype: ``boolean``


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