/**
 * Initializes the logic which:
 *
 * 1. Subscribes keydown and mousedown events. (It will only do it once per window,
 *    so it's safe to call this method multiple times.)
 * 2. When the user presses directional keyboard keys, adds the 'ms-Fabric--isFocusVisible' classname
 *    to the document body, removes the 'ms-Fabric-isFocusHidden' classname.
 * 3. When the user clicks a mouse button, adds the 'ms-Fabric-isFocusHidden' classname to the
 *    document body, removes the 'ms-Fabric--isFocusVisible' classname.
 *
 * This logic allows components on the page to conditionally render focus treatments based on
 * the existence of global classnames, which simplifies logic overall.
 *
 * @param window - the window used to add the event listeners
 * @deprecated Use useFocusRects hook or FocusRects component instead.
 */
export declare function initializeFocusRects(window?: Window): void;