code: func ConcatenateBytes(data ...[]byte) []byte {
  	finalLength := 0
  	for _, slice := range data {
  		finalLength += len(slice)
  	}
  	result := make([]byte, finalLength)
  	last := 0
  	for _, slice := range data {
  		for i := range slice {
  			result[i+last] = slice[i]
  		}
  		last += len(slice)
  	}
  	return result
  }
docs: // ConcatenateBytes is useful for combining multiple arrays of bytes, especially for
  // signatures or digests over multiple fields