'Testing the Union aggregate of 3D models.'

def test03a_union(self):

    ref_ewkt = 'SRID=4326;MULTIPOINT(-123.305196    48.462611    15,-104.609252    38.255001    1433,-97.521157    34.464642    380,-96.801611    32.782057    147,-95.363151    29.763374    18,-95.23506    38.971823    251,-87.650175    41.850385    181,174.783117    -41.315268    14)'
    ref_union = GEOSGeometry(ref_ewkt)
    union = City3D.objects.aggregate(Union('point'))['point__union']
    self.assertTrue(union.hasz)
    self.assertEqual(ref_union, union)
