import { OverlayChangeEvent, OverlayChangeSubscriber } from "../../typing/open-overlay";
declare class PubSub {
    private subscribers;
    /** Call `fn` whenever a new change is publisched on OverlayChanges channel */
    subscribeToOverlayChanges(fn: OverlayChangeSubscriber): void;
    /**
     * Call `fn` whenever a new change for `index` are publisched
     * on OverlayChanges channel
     */
    subscribeToSpecificOverlayChanges(index: number, fn: OverlayChangeSubscriber): void;
    /** Publish a change on OverlayChanges channel  */
    publishToOverlayChanges(change: OverlayChangeEvent): void;
}
export { PubSub, };
export default PubSub;