The PluginServletFilter class should be final
@@ -59,7 +59,7 @@ import org.kohsuke.accmod.restrictions.NoExternalUse;
*
* @see SecurityRealm
*/
-public class PluginServletFilter implements Filter, ExtensionPoint {
+public final class PluginServletFilter implements Filter, ExtensionPoint {
private final List<Filter> list = new CopyOnWriteArrayList<>();
private /*almost final*/ FilterConfig config;
