public static <A,B extends Comparable<? super B>> A indexedBinaryGetLow(List<A> list,
			F1<A, B> get, B key) {
		int search = searchIndexedBinary(list, get, key);
		if (search== -1) {
			return null;
		}
		if (search < 0) {
			return list.get(-search -1 -1);
		}
		return list.get(search);
	}