/**
 * Subject class to implement the observer pattern.
 * Observer is passed as a callback function.
 * Observers recive published object to read its properties
 * and call its methods to get its current state.
 * */
export declare class Subject<Type> {
    observers: ((object: Type) => void)[];
    subscribe(observer: (object: Type) => void): void;
    unsubscribe(observer: (object: Type) => void): void;
    publish(object: Type): void;
}