/**
 * Call a callback on a component and all of its child/nested components.
 * At each stage, the value of the component is set to the returned value
 * from the callback.
 *
 * @param {*} root The root component to call the callback on.
 * @param {*} callback The callback to call. It should take a single
 *                     component as an argument and return the new
 *                     desired value for that component.
 * @returns The result of calling callback on root.
 *          null if root is not valid.
 *          root if callback is not valid.
 */
declare const applyToComponentTree: (root: any, callback: any) => any;
export default applyToComponentTree;