default Comparator<V> ofIndex(final int index) {
		return (a, b) -> compare(a, b, index);
	}
Return a comparator which takes the component at the give {@code index}
for comparison two objects of type {@code T}.

@param index the component index
@return the component comparator for the given {@code index}
jenetics.ext/src/main/java/io/jenetics/ext/moea/ElementComparator.java