import 'intersection-observer';
export declare const observingCollection: {
    [serializedIntersectionObserverOptions: string]: {
        serializedOptions: string;
        intersectionObserver: IntersectionObserver;
        elements: Element[];
    };
};
export declare function observe(el: Element, options?: IntersectionObserverInit): void;
export declare function unobserve(el: Element, options?: IntersectionObserverInit): void;