code: def dump(self):
          
          try:
              topo = project_to_topology(self)
              path = self._topology_file()
              log.debug("Write %s", path)
              with open(path + ".tmp", "w+", encoding="utf-8") as f:
                  json.dump(topo, f, indent=4, sort_keys=True)
              shutil.move(path + ".tmp", path)
          except OSError as e:
              raise aiohttp.web.HTTPInternalServerError(text="Could not write topology: {}".format(e))
docs: Dump topology to disk