@Override
    public void chargeSystemResourceUsage(QuotaName quotaName, double usageCost) {
      if (throwSystemResourceChargeException || throwException) {
        throw new RuntimeException("test exception");
      }
      super.chargeSystemResourceUsage(quotaName, usageCost);
    }
Run with both request throttling enabled, as well as disabled.
@return an array with both {@code false} and {@code true}.
ambry-quota/src/test/java/com/github/ambry/quota/capacityunit/AmbryCUQuotaEnforcerTest.java