@Override
    public void openNode()
    {
        // The root of the outline hierarchy is not an OutlineItem and cannot be opened or closed
    }
@Test
    void outlinesCount()
    {
        PDDocumentOutline outline = new PDDocumentOutline();
        PDOutlineItem root = new PDOutlineItem();
        outline.addLast(root);
        assertEquals(1, outline.getOpenCount());
        root.addLast(new PDOutlineItem());
        assertEquals(-1, root.getOpenCount());
        assertEquals(1, outline.getOpenCount());
        root.addLast(new PDOutlineItem());
        assertEquals(-2, root.getOpenCount());
        assertEquals(1, outline.getOpenCount());
        root.openNode();
        assertEquals(2, root.getOpenCount());
        assertEquals(3, outline.getOpenCount());
    }