code: def test_groupby_expanding_kurt(self):
      self._test_groupby_expanding_func("kurt")
  
file_path: spark/python/pyspark/pandas/tests/window/test_groupby_expanding_adv.py
imports: from pyspark.testing.pandasutils import PandasOnSparkTestCase, TestUtils
  from pyspark.pandas.tests.window.test_groupby_expanding import GroupByExpandingTestingFuncMixin
label_desc: Use image node_id 5 for calling the GroupByExpandingAdvMixin obj's underlying member method code with example usage: obj.test_groupby_expanding_kurt() without return types