class_docstr: Base TestCase for running tests inside the given contexts.
  
  It ensures that all contexts are entered before any test starts and are exited
  upon all tests completion.
code: def setUpClass(cls):
      super().setUpClass()
  
      # Keep track of all entered contexts
      cls._stack = contextlib.ExitStack()
      for cm in cls._context_managers():
          cls._stack.enter_context(cm)
  
file_path: datasets/tensorflow_datasets/testing/test_case_in_context.py
imports: from collections.abc import Sequence
  import contextlib
  from typing import Any, ContextManager
  import unittest
label_desc: Use image node_id 2 for calling the TestCaseInContext obj's underlying member method code with example usage: obj.setUpClass(cls) without return types