@Override
    public float getSystemResourceUsage(QuotaName quotaName) {
      throwExceptionIfNeeded();
      return super.getSystemResourceUsage(quotaName);
    }
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