echo
----
{
  b := &kv.Batch{}
  b.Put(tk(2), sv(2)) // context canceled
  b.GetForUpdate(tk(1)) // context canceled
  b.ScanForUpdate(tk(1), tk(3)) // context canceled
  b.ReverseScan(tk(1), tk(3)) // context canceled
  db0.Run(ctx, b) // context canceled
}
