code: function validate(cmd, args, info) {
    AbstractCommand.prototype.validate.apply(this, arguments);
    if(args[0]) {
      var arg = ('' + args[0]).toLowerCase();
      if(arg !== Constants.SHUTDOWN.SAVE && arg !== Constants.SHUTDOWN.NOSAVE) {
        throw CommandSyntax;
      }
  
      // rewrite with boolean
      args[0] = (arg === Constants.SHUTDOWN.SAVE);
    }
  }
docs: Validate the SHUTDOWN command.