docstr: Tests the `size` property.
code: def test_size(self):
      """Tests the `size` property."""
      assert self.df.sindex.size == self.expected_size
  
imports: from math import sqrt
  import numpy
  import pandas
  import pytest
  import shapely
  from numpy.testing import assert_array_equal
  from shapely.geometry import GeometryCollection, LineString, MultiPolygon, Point, Polygon, box
  import geopandas
  from geopandas import GeoDataFrame, GeoSeries, read_file
  from geopandas import _compat
label_desc: Use image node_id 26 for calling the TestShapelyInterface obj's underlying member method code with example usage: obj.test_size() without return types