code: def run(cls):
          
          if not all(v is None for v in cls._services.values()):
              cls._set_host_id()
              cls._setup_logging()
              cls._set_process_name()
              cls._set_signal_handlers()
              cls._start_server()
          else:
              cls._logger.error('No services to host')
docs: Fires up the event loop and starts serving attached services