code: def df():
      return pd.DataFrame(
          columns=["a", "b", "x", "y"],
          data=[
              ["a", "g", 1, 0.2],
              ["b", "h", 3, 0.5],
              ["a", "f", 2, 0.8],
              ["a", "h", 1, 0.3],
              ["b", "f", 2, 0.4],
          ],
      )
  
file_path: seaborn/tests/_core/test_groupby.py
imports: import numpy
  import pandas
  import pytest
  from numpy.testing import assert_array_equal
  from seaborn._core.groupby import GroupBy
label_desc: Use image node_id 1 for calling a global function with example usage: df() and returns: pd