pkg net, method (*UnixListener) SyscallConn() (syscall.RawConn, error)
pkg net/smtp, method (*Client) Noop() error
pkg os, func IsTimeout(error) bool
pkg os, method (*File) SetDeadline(time.Time) error
pkg os, method (*File) SetReadDeadline(time.Time) error
pkg os, method (*File) SetWriteDeadline(time.Time) error
pkg os, method (*PathError) Timeout() bool
pkg os, method (*SyscallError) Timeout() bool

		b = b[:len(b)+n]
		if err != nil {
			if errors.Is(err, io.EOF) {
				err = nil
			}
			return b, err
		}
	}
}

// getDeadline will truncate the deadline so it is at least 1ms and at most MaxDeadline.
func getDeadline(d time.Duration) time.Duration {
	if d < time.Millisecond {
		return 0
	}
	if d > MaxDeadline {
		return MaxDeadline
	}
	return d
}

pkg net, type Conn interface { Close, LocalAddr, Read, RemoteAddr, SetDeadline, SetReadDeadline, SetWriteDeadline, Write }
pkg net, type Conn interface, Close() error
pkg net, type Conn interface, LocalAddr() Addr
pkg net, type Conn interface, Read([]uint8) (int, error)
pkg net, type Conn interface, RemoteAddr() Addr
pkg net, type Conn interface, SetDeadline(time.Time) error
pkg net, type Conn interface, SetReadDeadline(time.Time) error

func (c *Connection) newMuxClient(ctx context.Context) (*muxClient, error) {
	client := newMuxClient(ctx, atomic.AddUint64(&c.NextID, 1), c)
	if dl, ok := ctx.Deadline(); ok {
		client.deadline = getDeadline(time.Until(dl))
		if client.deadline == 0 {
			client.cancelFn(context.DeadlineExceeded)
			return nil, context.DeadlineExceeded
		}
	}
	for {
		// Handle the extremely unlikely scenario that we wrapped.