code: func SimpleHashFromHashers(items []Hasher) []byte {
  	hashes := make([][]byte, len(items))
  	for i, item := range items {
  		hash := item.Hash()
  		hashes[i] = hash
  	}
  	return simpleHashFromHashes(hashes)
  }
docs: // SimpleHashFromHashers computes a Merkle tree from items that can be hashed.