export declare function clone<T>(value: T, exceptKey?: string[]): T;
type Selector<T> = keyof T | ((item: T) => string);
export declare function sort<T>(arr: T[], option?: {
    selector?: Selector<T>;
    descending?: boolean;
} | undefined): T[];
export declare function group<T>(arr: T[], by: Selector<T>): {
    [key: string]: T[];
};
export declare function chunk<T>(list: T[], size: number): T[][];
export {};