// over multiple lines and we need to omit those properties.
        boolean skipNext = false;

        for (String line : lines) {
            if (skipNext) {
                if (line.endsWith("\\") == false) {
                    skipNext = false;
                }
                continue;
            }

        Map<Element, Element> map = Maps.newTreeMap();
        for (Element element : keys) {
          map.put(element, element);
        }
        return map;
      }
    },
    SkipList {
      @Override
      Map<Element, Element> create(Collection<Element> keys) {
        Map<Element, Element> map = new ConcurrentSkipListMap<>();
        for (Element element : keys) {
          map.put(element, element);