Element simplelist = document.createElement("simplelist");

            int columns = 3;
            if (classDoc.getSubClasses().size() <= 3) {
                // if there are only 3 or fewer known subtypes, render them
                // in a single column
                columns = 1;
            }
            simplelist.setAttribute("columns", String.valueOf(columns));
            simplelist.setAttribute("type", "vert");