code: def test_numericalize_2(self):
      mf = MatchingField()
      arr = [["a"], ["b"], ["c"]]
      mf.numericalize(arr)
  
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 10 for calling the ClassMatchingFieldTestCases obj's underlying member method code with example usage: obj.test_numericalize_2() without return types