import type { UmbDeepPartialObject } from '../type/deep-partial-object.type.js';
/**
 * Deep merge two objects.
 * @param target
 * @param ...sources
 * @param source
 * @param fallback
 */
export declare function umbDeepMerge<T extends {
    [key: string]: any;
}, PartialType extends UmbDeepPartialObject<T> = UmbDeepPartialObject<T>>(source: PartialType, fallback: T): T;