code: def test_preserve_crs(dfs, how):
      df1, df2 = dfs
      result = overlay(df1, df2, how=how)
      assert result.crs is None
      crs = "epsg:4326"
      df1.crs = crs
      df2.crs = crs
      result = overlay(df1, df2, how=how)
      assert result.crs == crs
  
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 12 for calling a global function with example usage: test_preserve_crs(dfs, how) without return types