ue(positionEquals(container, 0, 300, 0, 300), "container position ok");
          // vertically, |c1| |    c2    | |c3|
          assert.isTrue(positionEquals(c1, 0, 50, 0, 50), "child 1 position ok");
          assert.isTrue(positionEquals(c2, 50, 250, 0, 50), "child 2 position ok");
          assert.isTrue(positionEquals(c3, 250, 300, 0, 50), "child 3 position ok");
        });

        test('layout-flex, layout-flex-2, layout-flex-3 in a horizontal layout', function() {
          container.classList.add(