@Test public void commit_conflict(){

    DB db0 = tx.makeTx();
    long recid = db0.getEngine().put(111, Serializer.INTEGER_SERIALIZER);
    db0.commit();
    DB db1 = tx.makeTx();
    db1.getEngine().update(recid, 222, Serializer.INTEGER_SERIALIZER);
    try{
        tx.makeTx().getEngine().update(recid, 333, Serializer.INTEGER_SERIALIZER);
        fail("should throw exception");
    }catch(TxRollbackException e){
        //expected
    }
    //original transaction should complete well
    db1.commit();
    assertEquals(Integer.valueOf(222), tx.makeTx().getEngine().get(recid, Serializer.INTEGER_SERIALIZER));
}