public void every(int when, Closure closure) throws Exception {
   int cnt = plugin.getNextId();
   Trigger trigger = new SimpleTrigger("every " + cnt, SimpleTrigger.REPEAT_INDEFINITELY, when);
   plugin.configureJob(BoxContext.getCurrentContext(), cnt, trigger, createBlock(closure));
 }
 public void once(Closure closure) throws Exception {
   int cnt = plugin.getNextId();
   Trigger trigger = new SimpleTrigger("once " + cnt);
   plugin.configureJob(BoxContext.getCurrentContext(), cnt, trigger, createBlock(closure));
 }
 public void at(String when, final Closure closure) throws Exception {
   int cnt = plugin.getNextId();
   CronTrigger trigger = new CronTrigger("at " + cnt);
   trigger.setCronExpression(new CronExpression(when));
   plugin.configureJob(BoxContext.getCurrentContext(), cnt, trigger, createBlock(closure));
 }