</segmentedlist>
        <segmentedlist>
            <segtitle>Known Subtypes</segtitle>
            <seglistitem>
                <seg>
                    <simplelist columns="3" type="vert">
                        <member>
                            <apilink class="org.gradle.Subtype1"/>
                        </member>
                        <member>

                // in a single column
                columns = 1;
            }
            simplelist.setAttribute("columns", String.valueOf(columns));
            simplelist.setAttribute("type", "vert");
            for (ClassDoc subClass : classDoc.getSubClasses()) {
                Element member = document.createElement("member");
                Element apilink = document.createElement("apilink");