@Nonnull
    public static <T> Traverser<T> traverseArray(@Nonnull T[] array) {
        return new ArrayTraverser<>(array);
    }
@Test
    public void when_traverseArrayWithNull_then_skipNulls() {
        Traverser<Integer> trav = traverseArray(new Integer[] {1, null, 2});
        assertEquals(1, (int) trav.next());
        assertEquals(2, (int) trav.next());
        assertNull(trav.next());
    }