@abc.abstractmethod<EOL><INDENT>def get_schedule_slots_by_weekdays(self, weekdays):<DEDENT>
return<EOL>
Gets a ``ScheduleSlotList`` containing the given set of weekdays.

        :param weekdays: a set of weekdays
        :type weekdays: ``cardinal[]``
        :return: the returned ``ScheduleSlot`` list
        :rtype: ``osid.calendaring.ScheduleSlotList``
        :raise: ``InvalidArgument`` -- a ``weekday`` is negative
        :raise: ``NullArgument`` -- ``weekdays`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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