code: def decode(self, subtokens):
      
      if isinstance(subtokens, np.ndarray):
        # Note that list(subtokens) converts subtokens to a python list, but the
        # items remain as np.int32. This converts both the array and its items.
        subtokens = subtokens.tolist()
  
      if not subtokens:
        return ""
  
      assert isinstance(subtokens, list) and isinstance(subtokens[0], int), (
          "Subtokens argument passed into decode() must be a list of integers.")
  
      return _unicode_to_native(
          _join_tokens_to_string(self._subtoken_ids_to_tokens(subtokens)))
docs: Converts list of int subtokens ids into a string.