code: function keyboardNavigation() {
          var _this3 = this;
  
          if (this.events.hasOwnProperty('keyboard')) {
              return false;
          }
          this.events['keyboard'] = addEvent('keydown', {
              onElement: window,
              withCallback: function withCallback(event, target) {
                  event = event || window.event;
                  var key = event.keyCode;
                  if (key == 39) _this3.nextSlide();
                  if (key == 37) _this3.prevSlide();
                  if (key == 27) _this3.close();
              }
          });
      }
docs: Desktop keyboard navigation