@SafeVarargs
    public static <T> Traverser<T> traverseItems(T... items) {
        return traverseArray(items);
    }
@Test
    public void when_traverserOverArgsWithNull_then_skipNulls() {
        Traverser<Integer> trav = traverseItems(1, null, 2);
        assertEquals(1, (int) trav.next());
        assertEquals(2, (int) trav.next());
        assertNull(trav.next());
    }