code: def convert_tokens_to_string(self, tokens):
      return self.sp.DecodePieces(tokens)
  
imports: import os
  from typing import Dict, List, Optional, Union
  import numpy
  import sentencepiece
  from transformers.tokenization_utils import PreTrainedTokenizer
  from transformers.tokenization_utils_base import BatchEncoding, EncodedInput
  from transformers.utils import PaddingStrategy, logging
label_desc: Use image node_id 5 for calling the TextTokenizer obj's underlying member method code with example usage: obj.convert_tokens_to_string(tokens) and returns: self