public static <T extends Comparable<? super T>> T max(Collection<T> coll) {
		return isEmpty(coll) ? null : Collections.max(coll);
	}
@SuppressWarnings({"rawtypes", "unchecked"})
	@Test
	public void maxEmptyTest() {
		final List<? extends Comparable> emptyList = Collections.emptyList();
		assertNull(CollUtil.max(emptyList));
	}