export declare function P1<T, K1 extends keyof T>(obj: T, key1: K1): T[K1];
export declare function E1<T, K1 extends keyof T>(obj1: T, obj2: T, key1: K1): boolean;
export declare function P2<T, K1 extends keyof T, K2 extends keyof T[K1]>(obj: T, key1: K1, key2: K2): T[K1][K2];
export declare function E2<T, K1 extends keyof T, K2 extends keyof T[K1]>(obj1: T, obj2: T, key1: K1, key2: K2): boolean;
export declare function P3<T, K1 extends keyof T, K2 extends keyof T[K1], K3 extends keyof T[K1][K2]>(obj: T, key1: K1, key2: K2, key3: K3): T[K1][K2][K3];
export declare function promisify(value: any): any;