@utilities.arguments_not_none<EOL><INDENT>def search_among_repositories(self, repository_ids):<DEDENT>
self._id_list = repository_ids<EOL>
Execute this search among the given list of repositories.

        arg:    repository_ids (osid.id.IdList): list of repositories
        raise:  NullArgument - ``repository_ids`` is ``null``
        *compliance: mandatory -- This method must be implemented.*