declare function deepmerge(x: Partial, y: Partial, options?: deepmerge.Options): T; declare function deepmerge(x: Partial, y: Partial, options?: deepmerge.Options): T1 & T2; declare namespace deepmerge { export interface Options { arrayMerge?(target: any[], source: any[], options?: Options): any[]; clone?: boolean; isMergeableObject?(value: object): boolean; } export function all (objects: object[], options?: Options): object; } export = deepmerge;