/**
 * Starts / ends an XR session.
 *
 * @param sessionMode an XR session mode: 'inline' | 'immersive-vr' | 'immersive-ar'
 * @param sessionInit an XRSessionInit object
 * @param force Whether this button should only enter / exit an `XRSession`. Default is to toggle both ways
 * @returns
 */
export declare const toggleXRSession: (sessionMode: XRSessionMode, sessionInit?: (XRSessionInit & {
    domOverlay?: {
        root: HTMLElement;
    } | undefined;
}) | undefined, force?: "enter" | "exit") => Promise<XRSession | undefined>;