code: function onError(err) {
      // jshint validthis: true
      notifier.notify({
          title: err.plugin + ' Error',
          message: err.message
      });
      $.util.log(err.toString());
      $.util.beep();
      if (isWatching) {
          this.emit('end');
      } else {
          process.exit(1);
      }
  }
docs: **********************************************************************
  Functions/Utilities
   Desktop notifications of errors