code: def test_preprocessing_dtype(self):
      super(NumericalImputationTest, self)._test_preprocessing_dtype(
          NumericalImputation, add_NaNs=True
      )
  
file_path: auto-sklearn/test/test_pipeline/components/data_preprocessing/test_numerical_imputation.py
imports: from scipy import sparse
  from autosklearn.pipeline.components.data_preprocessing.imputation.numerical_imputation import NumericalImputation
  from autosklearn.pipeline.util import PreprocessingTestCase, _test_preprocessing
label_desc: Use image node_id 3 for calling the NumericalImputationTest obj's underlying member method code with example usage: obj.test_preprocessing_dtype() without return types