code: def test_size(self):
      pdf = pd.DataFrame(
          {"A": [1, 2, 2, 3, 3, 3], "B": [1, 1, 2, 3, 3, 3]}
      )
      psdf = ps.from_pandas(pdf)
      self.assert_eq(
          psdf.groupby("A").size().sort_index(),
          pdf.groupby("A").size().sort_index(),
      )
      self.assert_eq(
          psdf.groupby("A")["B"].size().sort_index(),
          pdf.groupby("A")["B"].size().sort_index(),
      )
      self.assert_eq(
          psdf.groupby("A")[["B"]].size().sort_index(),
          pdf.groupby("A")[["B"]].size().sort_index(),
      )
      self.assert_eq(
          psdf.groupby(["A", "B"]).size().sort_index(),
          pdf.groupby(["A", "B"]).size().sort_index(),
      )
  
      # multi-index columns
      columns = pd.MultiIndex.from_tuples([("X", "A"), ("Y", "B")])
      pdf.columns = columns
      psdf.columns = columns
  
      self.assert_eq(
          psdf.groupby(("X", "A")).size().sort_index(),
          pdf.groupby(("X", "A")).size().sort_index(),
      )
      self.assert_eq(
          psdf.groupby([("X", "A"), ("Y", "B")]).size().sort_index(),
          pdf.groupby([("X", "A"), ("Y", "B")]).size().sort_index(),
      )
  
file_path: spark/python/pyspark/pandas/tests/groupby/test_size.py
imports: import unittest
  import pandas
  import pyspark.pandas
  from pyspark.testing.pandasutils import PandasOnSparkTestCase
label_desc: Use image node_id 1 for calling the SizeTestsMixin obj's underlying member method code with example usage: obj.test_size() without return types