code: def test_all_columns(self):
      test_df = pd.DataFrame([[1, 2, 3], [4, 5, 6]], index=[0, 1])
  
      # should not raise an exception
      dataframe_functions.check_for_nans_in_columns(test_df)
  
      test_df = pd.DataFrame([[1, 2, 3], [4, np.NaN, 6]], index=[0, 1])
  
      self.assertRaises(
          ValueError,
          dataframe_functions.check_for_nans_in_columns,
          test_df,
      )
  
imports: import warnings
  from unittest import TestCase
  import numpy
  import pandas
  from pandas.testing import assert_frame_equal, assert_series_equal
  from tests.fixtures import warning_free
  from tsfresh import extract_relevant_features
  from tsfresh.feature_extraction.settings import MinimalFCParameters
  from tsfresh.utilities import dataframe_functions
label_desc: Use image node_id 1 for calling the CheckForNanTestCase obj's underlying member method code with example usage: obj.test_all_columns() without return types