code: def test_invalid_converter_source(self):
      with pytest.raises(ValueError) as e:
          converter.convert(None, source="invalid")
      expected_msg = r'Unrecognized value of argument "source": .*'
      e.match(expected_msg)
  
imports: import numpy
  import os
  import six
  import pytest
  import shutil
  import tempfile
  import coremltools
  import coremltools.converters
  from coremltools._deps import _IS_MACOS
  import coremltools.proto.FeatureTypes_pb2
  from coremltools import TensorType, ImageType, RangeDim, EnumeratedShapes
  from coremltools.converters.mil.testing_utils import random_gen
  from coremltools.converters.mil.frontend.tensorflow.converter import TFConverter
  from coremltools.converters.mil.frontend.tensorflow.test.testing_utils import frontend, make_tf_graph, run_compare_tf, get_tf_keras_io_names
label_desc: Use image node_id 11 for calling the TestTf1ModelFormats obj's underlying member method code with example usage: obj.test_invalid_converter_source() without return types