echo
----
db0.Put(ctx, tk(1), sv(1)) // @0.000000001,0 <nil>
db0.Txn(ctx, func(ctx context.Context, txn *kv.Txn) error {
  txn.SetIsoLevel(isolation.Serializable)
  txn.DelRange(ctx, tk(1), tk(3), true /* @s2 */) // (/Table/100/"0000000000000001", <nil>)
  txn.Put(ctx, tk(2), sv(3)) // <nil>
  return nil
}) // @0.000000002,0 <nil>
/Table/100/"0000000000000001"/0.000000001,0 @ s1 v1
/Table/100/"0000000000000001"/0.000000002,0 @ s2 <nil>
/Table/100/"0000000000000002"/0.000000003,0 @ s3 v3
committed serializable txn non-atomic timestamps: [dr.d]/Table/100/"0000000000000001":0.000000002,0-><nil>@s2 [dr.s]/Table/100/"000000000000000{1"-3"}:{gap:[<min>, 0.000000001,0),[0.000000003,0, <max>)}->[] [w]/Table/100/"0000000000000002":0.000000003,0->v3@s3
