pub fn set_request_nonce(&mut self, request_nonce: Bytes) {
        match *self {
            #[cfg(feature = "aead-cipher-2022")]
            Self::Aead2022(ref mut writer) => writer.set_request_salt(request_nonce),
            _ => {
                let _ = request_nonce;
                panic!("only AEAD-2022 cipher could send request salt");
            }
        }
    }
Set request nonce (for server stream of AEAD2022)
crates/shadowsocks/src/relay/tcprelay/crypto_io.rs