export declare function deepAssign<T, U>(target: T, source: U): T & U;
export declare function deepAssign<T, U, V>(target: T, source1: U, source2: V): T & U & V;
export declare function deepAssign<T, U, V, W>(target: T, source1: U, source2: V, source3: W): T & U & V & W;