@abc.abstractmethod<EOL><INDENT>def has_weekly_interval(self):<DEDENT>
return<EOL>
Tests if this schedule has a weekly interval.

        If ``true,`` ``has_fixed_interval()`` must be ``false``.

        :return: ``true`` if there is a weekly interval, ``false`` otherwise
        :rtype: ``boolean``


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