code: def test_return_endpoint(self):
      assert substring(self.line1, 500, 600).equals(Point(2, 0))
      assert substring(self.line1, 500, 500).equals(Point(2, 0))
      assert substring(self.line1, 1, 1.1, True).equals(Point(2, 0))
      assert substring(self.line1, 1.1, 1.1, True).equals(Point(2, 0))
  
imports: import json
  import unittest
  import pytest
  from shapely.errors import GeometryTypeError
  from shapely.geometry import LineString, Point, shape
  from shapely.ops import substring
label_desc: Use image node_id 3 for calling the SubstringTestCase obj's underlying member method code with example usage: obj.test_return_endpoint() without return types