code: def get_tokenizer(tokenizer, lang=None):
      if isinstance(tokenizer, BaseTokenizer):
          return tokenizer
      else:
          if tokenizer == "moses":
              return MosesTokenizer(lang=lang)
          elif tokenizer == "whitespace":
              return WhitespaceTokenizer()
          elif tokenizer == "jieba":
              return JiebaTokenizer()
          else:
              raise NotImplementedError
  
imports: import argparse
  import os
  import multiprocessing
  import time
  import numpy
  import warnings
  import re
  from gluonnlp.data.filtering import MosesNormalizer
  from gluonnlp.data.tokenizers import MosesTokenizer, BaseTokenizer, WhitespaceTokenizer, JiebaTokenizer
  from typing import List, Union, Optional
label_desc: Use image node_id 1 for calling a global function with example usage: get_tokenizer(tokenizer, lang) and returns: tokenizer, MosesTokenizer, WhitespaceTokenizer, JiebaTokenizer