class_docstr: Unit test class for testing scikit-learn converter.
code: def test_conversion_bad_inputs(self):
      # Error on converting an untrained model
      with self.assertRaises(TypeError):
          model = OneHotEncoder()
          spec = sklearn.convert(model, "data", "out")
  
      # Check the expected class during conversion.
      with self.assertRaises(TypeError):
          from sklearn.linear_model import LinearRegression
  
          model = LinearRegression()
          spec = sklearn.convert(model, "data", "out")
  
file_path: coremltools/coremltools/test/sklearn_tests/test_one_hot_encoder.py
imports: import unittest
  from copy import copy
  from distutils.version import StrictVersion
  import numpy
  from coremltools._deps import _HAS_SKLEARN, _SKLEARN_VERSION
  from coremltools.models.utils import _is_macos, _macos_version, evaluate_transformer
label_desc: Use image node_id 8 for calling the OneHotEncoderScikitTest obj's underlying member method code with example usage: obj.test_conversion_bad_inputs() without return types