code: def test_invalid_format_invalid_extension(self):
      _, invalid_filename = tempfile.mkstemp(
          suffix=".invalid", prefix=self.saved_model_dir
      )
      with pytest.raises(NotImplementedError) as e:
          converter.convert(invalid_filename, source=frontend)
      e.match(r"Expected model format: .* .h5")
  
imports: import os
  import shutil
  import tempfile
  import pytest
  import coremltools.converters
  from coremltools.converters.mil.input_types import TensorType
  from coremltools.converters.mil.frontend.tensorflow.test.testing_utils import get_tf_keras_io_names
  from coremltools.converters.mil.frontend.tensorflow.test import testing_utils
  from coremltools.converters.mil.frontend.tensorflow2.test.testing_utils import make_tf2_graph, run_compare_tf2
  from coremltools.converters.mil.frontend.tensorflow.test.test_load import frontend, TestTf1ModelInputsOutputs
label_desc: Use image node_id 11 for calling the TestTf2ModelFormats obj's underlying member method code with example usage: obj.test_invalid_format_invalid_extension() without return types