protected PolicyFailure limitExceededFailure(IPolicyFailureFactoryComponent failureFactory) {
        PolicyFailure failure = failureFactory.createFailure(PolicyFailureType.Other,
                PolicyFailureCodes.BYTE_QUOTA_EXCEEDED,
                Messages.i18n.format("TransferQuotaPolicy.RateExceeded")); //$NON-NLS-1$
        failure.setResponseCode(429);
        return failure;
    }
Called to send a 'quota exceeded' failure.
gateway/engine/policies/src/main/java/io/apiman/gateway/engine/policies/TransferQuotaPolicy.java