def METHOD_NAME(self, old_rule):
    rule = {'state': old_rule['state']}
    if 'track' in old_rule:
        try:
            rule['track'] = [self._track_id_map[t] for t in old_rule['track']]
        except KeyError:
            return None
    if 'contribution_type' in old_rule:
        try:
            rule['contribution_type'] = [self._contrib_type_id_map[ct] for ct in old_rule['contribution_type']]
        except KeyError:
            return None
    return rule