/**
 * 添加一行，默认添加到最后一行
 *
 * @category Utils
 * @template T
 * @param {T[]} arr
 * @param {T} addItem
 * @param {number} [insertIndex=arr.length]
 * @return {*}
 */
export declare const onAddData: <T = any>(arr: T[], addItem: T, insertIndex?: number) => T[];