code: def do_restart_service(self, service):
          
          if not self.has_cluster():
              return None
  
          if self.service_action(service=service, action="restart"):
              print("%s is being restarted" % (service))
          else:
              print("Error restarting service")
              return None
docs: Restart a service
          Usage:
              > restart_service <service>