/**
 * Helper to get the window object. The helper will make sure to use a cached variable
 * of "window", to avoid overhead and memory leaks in IE11. Note that in popup scenarios the
 * window object won't match the "global" window object, and for these scenarios, you should
 * pass in an element hosted within the popup.
 *
 * @public
 */
export declare function getWindow(rootElement?: Element | null): Window | undefined;