code: def test_flags_undefined(self):
      tpu_test_wrapper.maybe_define_flags()
  
      self.assertIn("tpu", flags.FLAGS)
      self.assertIn("zone", flags.FLAGS)
      self.assertIn("project", flags.FLAGS)
      self.assertIn("model_dir", flags.FLAGS)
  
imports: import importlib.util
  import os
  from absl.testing import flagsaver
  from tensorflow.python.platform import flags
  from tensorflow.python.platform import test
  from tensorflow.python.tpu import tpu_test_wrapper
label_desc: Use image node_id 1 for calling the TPUTestWrapperTest obj's underlying member method code with example usage: obj.test_flags_undefined() without return types