String service = keys.length >= 3 ? keys[2] : null;
String request = keys.length >= 4 ? keys[3] : null;
String format = keys.length >= 5 ? keys[4] : null;
OWSRequestMatcher requestMatcher = new OWSRequestMatcher(service, request, format);
KeyGenerator keyGenerator = buildKeyGenerator(keys, value);
return new RateFlowController(requestMatcher, rate, interval, delay, keyGenerator);
}