private Map<String, Map<String, String>> getPrefix(Map<String, String> options, int lim) {
        return options.entrySet()
                .stream()
                .map(e -> splitEntry(e, lim))
                .filter(Objects::nonNull)
                .collect(Collectors.toMap(
                        Entry::getKey,
                        Entry::getValue,
                        (e1, e2) -> {
                            Map<String, String> hm = new HashMap<>(e1);
                            hm.putAll(e2);
                            return hm;
                        }
                ));
    }
@author Marc Savy {@literal <marc@blackparrotlabs.io>}
manager/api/security/src/main/java/io/apiman/manager/api/security/impl/DiscoverabilityOptionsParser.java