code: def _byte_encode(self, token):
      
      # Vocab ids for all bytes follow ids for the subwords
      offset = len(self._subwords)
      if token == "_":
        return [len(self._subwords) + ord(" ")]
      return [i + offset for i in list(bytearray(tf.compat.as_bytes(token)))]
docs: Encode a single token byte-wise into integer ids.