def test02_proxy(self):
        "Testing Lazy-Geometry support (using the GeometryProxy)."
        #### Testing on a Point
        pnt = Point(0, 0)
        nullcity = City(name='NullCity', point=pnt)
        nullcity.save()

        # Making sure TypeError is thrown when trying to set with an
        #  incompatible type.
        for bad in [5, 2.0, LineString((0, 0), (1, 1))]:
            try:
                nullcity.point = bad
            except __HOLE__:
                pass
            else:
                self.fail('Should throw a TypeError')

        # Now setting with a compatible GEOS Geometry, saving, and ensuring
        #  the save took, notice no SRID is explicitly set.
        new = Point(5, 23)
        nullcity.point = new

        # Ensuring that the SRID is automatically set to that of the 
        #  field after assignment, but before saving.
        self.assertEqual(4326, nullcity.point.srid)
        nullcity.save()

        # Ensuring the point was saved correctly after saving
        self.assertEqual(new, City.objects.get(name='NullCity').point)

        # Setting the X and Y of the Point
        nullcity.point.x = 23
        nullcity.point.y = 5
        # Checking assignments pre & post-save.
        self.assertNotEqual(Point(23, 5), City.objects.get(name='NullCity').point)
        nullcity.save()
        self.assertEqual(Point(23, 5), City.objects.get(name='NullCity').point)
        nullcity.delete()

        #### Testing on a Polygon
        shell = LinearRing((0, 0), (0, 100), (100, 100), (100, 0), (0, 0))
        inner = LinearRing((40, 40), (40, 60), (60, 60), (60, 40), (40, 40))

        # Creating a State object using a built Polygon
        ply = Polygon(shell, inner)
        nullstate = State(name='NullState', poly=ply)
        self.assertEqual(4326, nullstate.poly.srid) # SRID auto-set from None
        nullstate.save()

        ns = State.objects.get(name='NullState')
        self.assertEqual(ply, ns.poly)
        
        # Testing the `ogr` and `srs` lazy-geometry properties.
        if gdal.HAS_GDAL:
            self.assertEqual(True, isinstance(ns.poly.ogr, gdal.OGRGeometry))
            self.assertEqual(ns.poly.wkb, ns.poly.ogr.wkb)
            self.assertEqual(True, isinstance(ns.poly.srs, gdal.SpatialReference))
            self.assertEqual('WGS 84', ns.poly.srs.name)

        # Changing the interior ring on the poly attribute.
        new_inner = LinearRing((30, 30), (30, 70), (70, 70), (70, 30), (30, 30))
        ns.poly[1] = new_inner
        ply[1] = new_inner
        self.assertEqual(4326, ns.poly.srid)
        ns.save()
        self.assertEqual(ply, State.objects.get(name='NullState').poly)
        ns.delete()
dataset/ETHPy150Open dcramer/django-compositepks/django/contrib/gis/tests/geoapp/tests_mysql.py/GeoModelTest.test02_proxy