code: def test_duplicate_column_name(dfs, how):
      if how == "difference":
          pytest.skip("Difference uses columns from one df only.")
      df1, df2 = dfs
      df2r = df2.rename(columns={"col2": "col1"})
      res = overlay(df1, df2r, how=how)
      assert ("col1_1" in res.columns) and ("col1_2" in res.columns)
  
imports: import os
  import numpy
  import pandas
  from shapely import make_valid
  from shapely.geometry import Point, Polygon, LineString, GeometryCollection, box
  import geopandas
  from geopandas import GeoDataFrame, GeoSeries, overlay, read_file
  from geopandas._compat import PANDAS_GE_20
  from geopandas.testing import assert_geodataframe_equal, assert_geoseries_equal
  import pytest
label_desc: Use image node_id 10 for calling a global function with example usage: test_duplicate_column_name(dfs, how) without return types