@abc.abstractmethod<EOL><INDENT>def set_items_shuffled(self, shuffle):<DEDENT>
pass<EOL>
Sets the shuffle flag.

        The shuffle flag may be overidden by other assessment sequencing
        rules.

        :param shuffle: ``true`` if the items are shuffled, ``false`` if the items appear in the designated order
        :type shuffle: ``boolean``
        :raise: ``InvalidArgument`` -- ``shuffle`` is invalid
        :raise: ``NoAccess`` -- ``Metadata.isReadOnly()`` is ``true``

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