export interface NextObserver<T> {
    next: (value: T) => void;
}
export interface Unsubscribable {
    unsubscribe(): void;
}
export interface Subscribable<T> {
    subscribe(next: (value: T) => void): Unsubscribable;
}
export interface BehaviorSubject<T> extends Subscribable<T> {
    readonly value: T;
}