export interface Unsubscribable {
    unsubscribe(): void;
}
export interface SubscriptionLike extends Unsubscribable {
    readonly closed: boolean;
    readonly done: Promise<void>;
}
export declare class Subscription implements SubscriptionLike {
    private readonly _collection;
    private readonly _done;
    closed: boolean;
    add(sub: (() => unknown) | Unsubscribable): void;
    remove(sub: (() => void) | Unsubscribable): void;
    unsubscribe(): void;
    get done(): Promise<void>;
}