// RegisterDecompressor registers or overrides a custom decompressor for a
// specific method ID. If a decompressor for a given method is not found,
// [Reader] will default to looking up the decompressor at the package level.
func (r *Reader) RegisterDecompressor(method uint16, dcomp Decompressor) {
	if r.decompressors == nil {
		r.decompressors = make(map[uint16]Decompressor)
	}
	r.decompressors[method] = dcomp
}

	return err
}

// RegisterCompressor registers or overrides a custom compressor for a specific
// method ID. If a compressor for a given method is not found, [Writer] will
// default to looking up the compressor at the package level.
func (w *Writer) RegisterCompressor(method uint16, comp Compressor) {
	if w.compressors == nil {
		w.compressors = make(map[uint16]Compressor)
	}
	w.compressors[method] = comp
}

// client closed the stream prematurely.
func newS2CompressReader(r io.Reader, on int64, encrypted bool) (rc io.ReadCloser, idx func() []byte) {
	pr, pw := io.Pipe()
	// Copy input to compressor
	opts := compressOpts
	if encrypted {
		// The values used for padding are not a security concern,
		// but we choose pseudo-random numbers instead of just zeros.