Error

        pub const Error = error{
            /// Another TCP Fast Open is already in progress.
            FastOpenAlreadyInProgress,
            /// Network session was unexpectedly closed by recipient.
            ConnectionResetByPeer,
            /// The output queue for a network interface was full. This generally indicates that the
            /// interface has stopped sending, but may be caused by transient congestion. (Normally,
            /// this does not occur in Linux. Packets are just silently dropped when a device queue
            /// overflows.)
            ///
            /// This is also caused when there is not enough kernel memory available.
            SystemResources,
            /// No route to network.
            NetworkUnreachable,
            /// Network reached but no route to host.
            HostUnreachable,
            /// The local network interface used to reach the destination is down.
            NetworkDown,
            /// The destination address is not listening.
            ConnectionRefused,
            /// The passed address didn't have the correct address family in its sa_family field.
            AddressFamilyUnsupported,
            /// Local end has been shut down on a connection-oriented socket, or
            /// the socket was never connected.
            SocketUnconnected,
            /// The remote peer did not respond to ongoing communication, causing the
            /// OS to abort the connection.
            ConnectionTimedOut,
            SocketNotBound,
        } || Io.UnexpectedError