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

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