@utilities.arguments_not_none<EOL><INDENT>def search_among_hierarchies(self, hierarchy_ids):<DEDENT>
self._id_list = hierarchy_ids<EOL>
Execute this search using a given list of hierarchies.

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