code: def test_size_series_dataframe():
      # https://github.com/pandas-dev/pandas/issues/11699
      df = DataFrame(columns=["A", "B"])
      out = Series(dtype="int64", index=Index([], name="A"))
      tm.assert_series_equal(df.groupby("A").size(), out)
  
file_path: pandas/pandas/tests/groupby/methods/test_size.py
imports: import numpy
  import pytest
  import pandas.util._test_decorators
  from pandas.core.dtypes.common import is_integer_dtype
  from pandas import DataFrame, Index, PeriodIndex, Series
  import pandas._testing
label_desc: Use image node_id 4 for calling a global function with example usage: test_size_series_dataframe() without return types