code: func (v *ContentAddressValidator) Validate(ch Chunk) bool {
  	data := ch.Data()
  	if l := len(data); l < 9 || l > chunk.DefaultSize+8 {
  		// log.Error("invalid chunk size", "chunk", addr.Hex(), "size", l)
  		return false
  	}
  
  	hasher := v.Hasher()
  	hasher.ResetWithLength(data[:8])
  	hasher.Write(data[8:])
  	hash := hasher.Sum(nil)
  
  	return bytes.Equal(hash, ch.Address())
  }
docs: // Validate that the given key is a valid content address for the given data