code: def get_alert(self, value):
          
          ret = 'OK'
          try:
              if value <= self.get_limit('critical', stat_name=self.plugin_name):
                  ret = 'CRITICAL'
              elif value <= self.get_limit('warning', stat_name=self.plugin_name):
                  ret = 'WARNING'
              elif value <= self.get_limit('careful', stat_name=self.plugin_name):
                  ret = 'CAREFUL'
          except (TypeError, KeyError) as e:
              # Catch TypeError for issue1373
              ret = 'DEFAULT'
  
          return ret
docs: Overwrite the default get_alert method.
  
          Alert is on signal quality where lower is better...
  
          :returns: string -- Signal alert