code: def test_init_2(self):
      mf = MatchingField()
      seq = "Hello, This is a test sequence for tokenizer."
      tok_seq = [
          "Hello",
          ",",
          "This",
          "is",
          "a",
          "test",
          "sequence",
          "for",
          "tokenizer",
          ".",
      ]
      self.assertEqual(mf.tokenize(seq), tok_seq)
  
imports: import os
  import shutil
  import unittest
  from collections import Counter
  from test import test_dir_path
  from nose.tools import *
  import torch
  from deepmatcher.data.dataset import MatchingDataset
  from deepmatcher.data.field import FastText, FastTextBinary, MatchingField, MatchingVocab, reset_vector_cache
  from torchtext.vocab import Vectors
  from urllib.parse import urljoin
  from urllib.request import pathname2url
label_desc: Use image node_id 2 for calling the ClassMatchingFieldTestCases obj's underlying member method code with example usage: obj.test_init_2() without return types