export declare function uniqueId(): string;
/**
 *
 * @param length 字符串长度 @default 32
 * @param chars 字符集 @default  '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
 */
export declare function randomString(length?: number, chars?: string): string;