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

        :param package_ids: list of packages
        :type package_ids: ``osid.id.IdList``
        :raise: ``NullArgument`` -- ``package_ids`` is ``null``

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