code: def test_init_1(self):
      fields = [
          ("left_a", MatchingField()),
          ("right_a", MatchingField()),
      ]
      col_naming = {
          "id": "id",
          "label": "label",
          "left": "left",
          "right": "right",
      }
      path = os.path.join(
          test_dir_path, "test_datasets", "sample_table_small.csv"
      )
      md = MatchingDataset(fields, col_naming, path=path)
      self.assertEqual(md.id_field, "id")
      self.assertEqual(md.label_field, "label")
      self.assertEqual(md.all_left_fields, ["left_a"])
      self.assertEqual(md.all_right_fields, ["right_a"])
      self.assertEqual(md.all_text_fields, ["left_a", "right_a"])
      self.assertEqual(md.canonical_text_fields, ["_a"])
  
imports: import io
  import os
  import shutil
  import unittest
  from test import test_dir_path
  import pandas
  from nose.tools import *
  import torch
  from deepmatcher.data.dataset import *
  from deepmatcher.data.field import FastText, MatchingField
  from deepmatcher.data.process import _make_fields, process
  from torchtext.utils import unicode_csv_reader
  from urllib.parse import urljoin
  from urllib.request import pathname2url
label_desc: Use image node_id 1 for calling the ClassMatchingDatasetTestCases obj's underlying member method code with example usage: obj.test_init_1() without return types