code: def test_fake_tokenizer():
      from src.utils import FakeTokenizer
  
      t = FakeTokenizer()
      assert t.num_tokens_from_string("How are you?") == 4
      assert t.num_tokens_from_string("<|endoftext|>") == 7
      try:
          t.encoding.encode("<|endoftext|>")
          raise RuntimeError("Shouldn't reach here")
      except ValueError as e:
          assert "disallowed special token" in str(e)
  
file_path: h2ogpt/tests/test_tokenizer.py
imports: import os
  import nltk
  import pytest
  from tests.utils import wrap_test_forked
  import re
  import time
label_desc: Use image node_id 5 for calling a global function with example usage: test_fake_tokenizer() without return types