docstr: Tests the `is_empty` property.
code: def test_is_empty(self):
      """Tests the `is_empty` property."""
      # create empty tree
      empty = geopandas.GeoSeries([], dtype=object)
      assert empty.sindex.is_empty
      empty = geopandas.GeoSeries([None])
      assert empty.sindex.is_empty
      empty = geopandas.GeoSeries([Point()])
      assert empty.sindex.is_empty
      # create a non-empty tree
      non_empty = geopandas.GeoSeries([Point(0, 0)])
      assert not non_empty.sindex.is_empty
  
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 28 for calling the TestShapelyInterface obj's underlying member method code with example usage: obj.test_is_empty() without return types