code: def areBackupsDegraded(self):
          
          slow_instances = []
          if self.acc_monitor:
              for instance in self.instances.backupIds:
                  if self.acc_monitor.is_instance_degraded(instance):
                      slow_instances.append(instance)
          else:
              for instance in self.instances.backupIds:
                  if self.is_instance_throughput_too_low(instance):
                      slow_instances.append(instance)
          return slow_instances
docs: Return slow instance.