func HuffmanDecode(w io.Writer, v []byte) (int, error) {
	buf := bufPool.Get().(*bytes.Buffer)
	buf.Reset()
	defer bufPool.Put(buf)
	if err := huffmanDecode(buf, 0, v); err != nil {
		return 0, err
	}
	return w.Write(buf.Bytes())
}
HuffmanDecode decodes the string in v and writes the expanded
result to w, returning the number of bytes written to w and the
Write call's return value. At most one Write call is made.
package hpack
import (
	"bytes"
	"errors"
	"io"
	"sync"
)
var bufPool = sync.Pool{
	New: func() interface{} { return new(bytes.Buffer) },
}