code: def test_init(self):
      tmp_dir = tempfile.TemporaryDirectory()
      dict_file = osp.join(tmp_dir.name, "fake_chars.txt")
      create_dummy_dict_file(dict_file)
      dict_cfg = dict(
          type="Dictionary",
          dict_file=dict_file,
          with_start=True,
          with_end=True,
          same_start_end=True,
          with_padding=True,
          with_unknown=True,
      )
      loss_cfg = dict(type="CEModuleLoss")
      MasterDecoder(dictionary=dict_cfg, module_loss=loss_cfg)
      tmp_dir.cleanup()
  
file_path: mmocr/tests/test_models/test_textrecog/test_decoders/test_master_decoder.py
imports: import os.path
  import tempfile
  from unittest import TestCase
  import torch
  from mmengine.structures import LabelData
  from mmocr.models.textrecog.decoders import MasterDecoder
  from mmocr.structures import TextRecogDataSample
  from mmocr.testing import create_dummy_dict_file
label_desc: Use image node_id 2 for calling the TestMasterDecoder obj's underlying member method code with example usage: obj.test_init() without return types