private static String[] arrayDifference(String[] allowed, String[] disallowed, String[] defaultItems) {
        List<String> allowL = new ArrayList<>(Arrays.asList(optionalVar(allowed, defaultItems)));
        List<String> disallowL = new ArrayList<>(Arrays.asList(optionalVar(disallowed, EMPTY)));
        allowL.removeAll(disallowL);
        return allowL.toArray(new String[allowL.size()]);
    }
Build {@link HttpClientOptions} using populated {@link TLSOptions}.

@author Marc Savy {@literal <msavy@redhat.com>}
gateway/platforms/vertx3/vertx3/src/main/java/io/apiman/gateway/platforms/vertx3/http/HttpClientOptionsFactory.java