/**
 * Merge and deep copy the values of all of the enumerable own properties of target object from source object to a new object
 * @param target The target object to get properties from.
 * @param source The source object from which to copy properties.
 * @return A new merged and deep copied object.
 */
export declare function mergeDeep<T extends object, S extends object>(target: T, source: S): T & S;