code: function(callback) {
        var app = this;
        // bind to the APP_EVENTS first
        $.each(this.APP_EVENTS, function(i, e) {
          app.bind(e, callback);
        });
        // next, bind to listener names (only if they dont exist in APP_EVENTS)
        $.each(this.listeners.keys(true), function(i, name) {
          if (app.APP_EVENTS.indexOf(name) == -1) {
            app.bind(name, callback);
          }
        });
        return this;
      }
docs: Will bind a single callback function to every event that is already being listened to in the app. This includes all the `APP_EVENTS` as well as any custom events defined with `bind()`.  Used internally for debug logging.