code: def test_groupby(self):
      for f, s in self.pts.groupby(lambda x: x % 2):
          assert type(s) is GeoSeries
  
imports: from pandas import DataFrame, Series
  from shapely.geometry import Point
  from geopandas import GeoDataFrame, GeoSeries
label_desc: Use image node_id 10 for calling the TestSeries obj's underlying member method code with example usage: obj.test_groupby() without return types