/** Restore prior userTimezone */
 public void undo() {
   ((LiferayTomcatServer) server).setUserTimezone(oldUserTimezone);
 }
 /** Execute setting the user timezone */
 public void execute() {
   oldUserTimezone = ((LiferayTomcatServer) server).getUserTimezone();
   ((LiferayTomcatServer) server).setUserTimezone(userTimezone);
 }