 rev = %d, want %d", i, rev, base+0)   }    r, err := s.Range([]byte("foo"), nil, RangeOptions{})   if err != nil {    t.Fatal(err)   }   wkvs := []mvccpb.KeyValue{    {Key: []byte("foo"), Value: []byte("bar"), CreateRevision: 0, ModRevision: 