code: def check_func(self, func):
      self.assert_eq(func(self.ks_start_date), func(self.pd_start_date))
  
imports: import datetime
  import unittest
  import numpy
  import pandas
  from pyspark import pandas
  from pyspark.testing.pandasutils import PandasOnSparkTestCase
  from pyspark.testing.sqlutils import SQLTestUtils
label_desc: Use image node_id 4 for calling the SeriesDateTimeTestsMixin obj's underlying member method code with example usage: obj.check_func(func) without return types