@property
    def null_srid(self):
        info = geos_version_info()
        if info['version'] == '3.0.0' and info['release_candidate']:
            return -1
        else:
            return None
this function adds a relative to a node:
dataset/ETHPy150Open CollabQ/CollabQ/vendor/django/contrib/gis/tests/test_geos.py/GEOSTest.null_srid--crossover with--dataset/ETHPy150Open kakwa/pygraph_redis/pygraph_redis/directed_graph.py/Directed_graph._add_relative