type Writer struct {
	err error
	buf []byte
	n   int
	wr  io.Writer
}

// NewWriterSize returns a new [Writer] whose buffer has at least the specified
// size. If the argument io.Writer is already a [Writer] with large enough
// size, it returns the underlying [Writer].
func NewWriterSize(w io.Writer, size int) *Writer {
	// Is it already a Writer?
	b, ok := w.(*Writer)
	if ok && len(b.buf) >= size {