code: def _create_dummy_dict_file(
      self,
      dict_file,
      chars=list("0123456789abcdefghijklmnopqrstuvwxyz"),
  ):  # NOQA
      with open(dict_file, "w") as f:
          for char in chars:
              f.write(char + "\n")
  
file_path: mmocr/tests/test_models/test_textrecog/test_decoders/test_aster_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 ASTERDecoder
  from mmocr.structures import TextRecogDataSample
label_desc: Use image node_id 2 for calling the TestASTERDecoder obj's underlying member method code with example usage: obj._create_dummy_dict_file(dict_file, chars) without return types