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

        :param interval: the new weekly interval
        :type interval: ``integer``
        :raise: ``InvalidArgument`` -- ``interval`` is invalid
        :raise: ``NoAccess`` -- ``interval`` cannot be modified

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