class_docstr: Tests tabular hot-flips on classification tasks.
class_docstr_tok: ["Tests","tabular","hot-flips","on","classification","tasks","."]
docstr: Tests the case when a feature is assigned None value.
code: def test_example_field_is_none(self):
      """Tests the case when a feature is assigned None value."""
      self._example["weight"] = None
      output = self._gen.generate(
          example=self._example,
          model=self._model,
          dataset=self._dataset,
          config=self._config,
      )
      self.assertNotEmpty(output)
  
imports: from unittest import mock
  from absl.testing import absltest
  from lit_nlp.api import dataset
  from lit_nlp.api import model
  from lit_nlp.api import types
  from lit_nlp.components import minimal_targeted_counterfactuals
  from lit_nlp.lib import caching
  import numpy
  import scipy.special
label_desc: Use image node_id 12 for calling the ClassificationTabularMtcTest obj's underlying member method code with example usage: obj.test_example_field_is_none() without return types