code: func NewRefHasher(hasher BaseHasherFunc, count int) *RefHasher {
  	h := hasher()
  	hashsize := h.Size()
  	c := 2
  	for ; c < count; c *= 2 {
  	}
  	return &RefHasher{
  		sectionLength: 2 * hashsize,
  		maxDataLength: c * hashsize,
  		hasher:        h,
  	}
  }
docs: // NewRefHasher returns a new RefHasher