private static <A> HashMap<Integer, A> valMap(List<Iterator<A>> iterators) {
		HashMap<Integer, A> vals = new HashMap<Integer, A>();
		int i = 0;
		for (Iterator<A> iterator : iterators) {
			if (iterator.hasNext()) {
				vals.put(i, iterator.next());
			}
			i++;
		}
		return vals;
	}