private QuartzExecBlock createBlock(final Closure closure) throws Exception {
   QuartzExecBlock block = new QuartzExecBlock(plugin, BoxContext.getCurrentContext(), closure);
   ExecContext.with(
       block,
       new ExecRunnable() {
         public void run() throws Exception {
           closure.call();
         }
       });
   return block;
 }
 public Object enclosing() throws Exception {
   return ExecContext.getEnclosing();
 }