nextElementIndex = this._getItemIndex(nextElement)\n    const isCycling = Boolean(this._interval)\n\n    let directionalClassName\n    let orderClassName\n    let eventDirectionName\n\n    if (direction === DIRECTION_NEXT) {\n      directionalClassName = CLASS_NAME_LEFT\n      orderClassName = CLASS_NAME_NEXT\n      eventDirectionName = DIRECTION_LEFT\n    } else {\n      directionalClassName = CLASS_NAME_RIGHT\n      orderClassName = CLASS_NAME_PREV\n      eventDirectionName = DIRECTION_RIGHT\n  ...