import OlMap from 'ol/Map.js';
import OlOverlay from 'ol/Overlay.js';
/**
 * Store and manage overlays (popups) on the map.
 */
export declare class Overlay {
    private readonly map;
    constructor(map: OlMap);
    /**
     * Add an overlay (with a group id) to the map.
     */
    addOverlay(overlayGroupUid: string, overlay: OlOverlay): void;
    /**
     * @returns all overlay for a specific group.
     */
    getOverlays(overlayGroupUid: string): OlOverlay[];
    /**
     * Clear from the map all existing overlays from a group.
     */
    clearOverlaysByGroupId(overlayGroupUid: string): void;
    /**
     * Set z-index of an overlay.
     * @static
     */
    static setOverlayZindex(overlay: OlOverlay, zIndex: number): void;
}