/**
 * #3306 Keeps the id references of a viewer (`for`, `aria-labelledby`, `aria-controls`, ...) inside the viewer.
 *
 * With several viewers on one page, every viewer renders the same ids. The browser resolves an id
 * reference to the first element with that id on the page, so the labels, descriptions and popups
 * of the second viewer would point into the first one. The ids themselves stay as they are (the
 * CSS and pdf.js rely on them); instead, every reference that resolves to an element outside this
 * viewer is re-pointed at this viewer's element with ARIA element reflection
 * (`element.ariaLabelledByElements = [...]`). A label's `for` becomes an `aria-labelledby`
 * reference plus a click handler.
 *
 * References that already resolve correctly are left alone, so the first viewer on the page - and
 * every single-viewer page - is never changed. Browsers without element reflection keep the plain
 * id references.
 */
export declare class ViewerLocalReferences {
    private readonly host;
    private observer;
    private updateScheduled;
    private readonly labelClickHandlers;
    constructor(host: HTMLElement);
    static isSupported(): boolean;
    /** fixes the current references, and the ones added later */
    start(): void;
    /** stops watching. References fixed so far stay fixed: they point into this viewer, which is never wrong. */
    stop(): void;
    destroy(): void;
    /** re-points every reference of this viewer that resolves to an element outside the viewer */
    update(): void;
    private fixReference;
    /** a label's `for` would label (and click) the first viewer's control */
    private replaceLabelFor;
    private findInViewer;
    private isRelevant;
    private scheduleUpdate;
}