synchronized int returnDbHandle(isc_db_handle db) {
synchronized int returnDbHandle(isc_db_handle db, FBConnectionRequestInfo cri) {
    synchronized int returnDbHandle(isc_db_handle db) {        if (db != null) {            freeDbHandles.addLast(db);            return useDbHandle(db, -1);        }        else {            return 0;        }    }