`Xdr` trait sealing and marking as unsafe
We might want to consider sealing the trait to avoid wrong implementations by users.
We must also think about making Xdr an unsafe trait, but my first impression is that leaving it save should be fine.
We might want to consider sealing the trait to avoid wrong implementations by users.
We must also think about making Xdr an unsafe trait, but my first impression is that leaving it save should be fine.