code: def _test_stat_functions(self, stat_func):
      pdf = pd.DataFrame(
          {
              "a": [np.nan, np.nan, np.nan],
              "b": [1, np.nan, 2],
              "c": [1, 2, 3],
          }
      )
      psdf = ps.from_pandas(pdf)
      self.assert_eq(stat_func(pdf.a), stat_func(psdf.a))
      self.assert_eq(stat_func(pdf.b), stat_func(psdf.b))
      self.assert_eq(stat_func(pdf), stat_func(psdf))
  
file_path: spark/python/pyspark/pandas/tests/test_generic_functions.py
imports: import numpy
  import pandas
  import pyspark.pandas
  from pyspark.testing.pandasutils import PandasOnSparkTestCase, TestUtils
label_desc: Use image node_id 1 for calling the GenericFunctionsTestsMixin obj's underlying member method code with example usage: obj._test_stat_functions(stat_func) without return types