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

        :param objective_ids: list of objectives
        :type objective_ids: ``osid.id.IdList``
        :raise: ``NullArgument`` -- ``objective_ids`` is ``null``

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