@abc.abstractmethod<EOL><INDENT>def set_weekdays(self, weekdays):<DEDENT>
pass<EOL>
Sets the weekdays of a weekly schedule.

        :param weekdays: the new weekday set
        :type weekdays: ``cardinal[]``
        :raise: ``InvalidArgument`` -- ``weekdays`` is invalid
        :raise: ``NoAccess`` -- ``weekdays`` cannot be modified
        :raise: ``NullArgument`` -- ``weekdays`` is ``null``

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