code: def test_get_class_of_subclass_from_file(self):
      c = get_class_of_subclass_from_file(
          "main", os.path.join(self.app_dir, "main.py"), "MONAILabelApp"
      )
      assert c
  
file_path: MONAILabel/tests/unit/utils/test_class_utils.py
imports: import os
  import unittest
  import monailabel.interfaces
  import monailabel.transform.post
  from monailabel.utils.others.class_utils import class_args_to_exp, get_class_names, get_class_of_subclass_from_file, init_class_from_exp
label_desc: Use image node_id 5 for calling the MyTestCase obj's underlying member method code with example usage: obj.test_get_class_of_subclass_from_file() without return types