PDOutlineNode getParent()
    {
        COSDictionary parent = getCOSObject().getCOSDictionary(COSName.PARENT);
        if (parent != null)
        {
            if (COSName.OUTLINES.equals(parent.getCOSName(COSName.TYPE)))
            {
                return new PDDocumentOutline(parent);
            }
            return new PDOutlineItem(parent);
        }
        return null;
    }
@Test
    void getParent()
    {
        PDOutlineItem child = new PDOutlineItem();
        root.addLast(child);
        PDDocumentOutline outline = new PDDocumentOutline();
        outline.addLast(root);
        assertNull(outline.getParent());
        assertEquals(outline, root.getParent());
        assertEquals(root, child.getParent());
    }