code: def _string_to_byte_list(self, data):
          
          bytes_length = 16
  
          m = self.digest()
          m.update(str.encode(data))
          hex_digest = m.hexdigest()
  
          return list(int(hex_digest[num * 2:num * 2 + 2], bytes_length)
                      for num in range(bytes_length))
docs: Creates a hex digest of the input string given to create the image,
          if it's not already hexadecimal
  
          Returns:
              Length 16 list of rgb value range integers
              (each representing a byte of the hex digest)