@abc.abstractmethod<EOL><INDENT>def search_among_items(self, item_ids):<DEDENT>
pass<EOL>
Execute this search among the given list of items.

        :param item_ids: list of items
        :type item_ids: ``osid.id.IdList``
        :raise: ``NullArgument`` -- ``item_ids`` is ``null``

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