code: def _check_quotas(self, time_ms):
          
          for metric in self._metrics:
              if metric.config and metric.config.quota:
                  value = metric.value(time_ms)
                  if not metric.config.quota.is_acceptable(value):
                      raise QuotaViolationError("'%s' violated quota. Actual: "
                                                "%d, Threshold: %d" %
                                                (metric.metric_name,
                                                 value,
                                                 metric.config.quota.bound))
docs: Check if we have violated our quota for any metric that
          has a configured quota