/**
 * Moves the DOM focus to the chart tab stop.
 * The proxy root is only tabbable while there is no description, otherwise one of the announcer
 * children holds the tab stop.
 * @param {HTMLDivElement | null} root The accessibility proxy root.
 * @returns {boolean} `true` when an element was focused.
 */
export declare function focusAccessibilityProxy(root: HTMLDivElement | null): boolean;