code: def multi_poly_gdf(donut_geometry):
      """Create a multi-polygon GeoDataFrame."""
      multi_poly = donut_geometry.union_all()
      out_df = GeoDataFrame(
          geometry=GeoSeries(multi_poly), crs="EPSG:3857"
      )
      out_df["attr"] = ["pool"]
      return out_df
  
imports: import numpy
  import shapely
  from shapely.geometry import Polygon, Point, LineString, LinearRing, GeometryCollection, MultiPoint, box
  import geopandas
  from geopandas import GeoDataFrame, GeoSeries, clip
  from geopandas.testing import assert_geodataframe_equal, assert_geoseries_equal
  import pytest
  from geopandas.tools.clip import _mask_is_list_like_rectangle
label_desc: Use image node_id 13 for calling a global function with example usage: multi_poly_gdf(donut_geometry) and returns: out_df