Op.isOptsWithFromKey & Op.isOptsWithPrefix accessor

[changhoi]

What would you like to be added?

It would be nice if the access function of Op.isOptsWithPrefix and Op.isOptsWithFromKey were provided. Only the accessor to this field was missing, is there a history related to it?

op := clientv3.OpDelete("mykey", clientv3.WithPrefix())
if op.IsOptsWithPrefix() {
  // ...
}

Why is this needed?

For making detail logs in application.