@SuppressWarnings("nls")
    public String toQueryString() { // TODO optimise
        List<Entry<String, String>> elems = getEntries();
        Collections.reverse(elems);
        return elems.stream()
                .map(pair -> URLEnc(pair.getKey()) + "=" + URLEnc(pair.getValue()))
                .collect(Collectors.joining("&"));
    }
Construct a QueryMap.

@param sizeHint the size hint
gateway/engine/beans/src/main/java/io/apiman/gateway/engine/beans/util/QueryMap.java