@Override
 @SuppressWarnings("unchecked")
 // doPrivileged() returns the correct type
 public Map<String, ? extends ServletRegistration> getServletRegistrations() {
   if (SecurityUtil.isPackageProtectionEnabled()) {
     return (Map<String, ? extends ServletRegistration>)
         doPrivileged("getServletRegistrations", null);
   } else {
     return context.getServletRegistrations();
   }
 }