pub fn is_unnamed(&self) -> bool {
        match *self {
            Self::SocketAddr(..) => false,
            #[cfg(unix)]
            Self::UnixSocketAddr(ref s) => s.is_unnamed(),
        }
    }
Check if it is unnamed (not binded to any valid address), only valid for `UnixSocketAddr`
crates/shadowsocks/src/manager/datagram.rs