/**
 * whitespace(elem [, isBlock]) removes extraneous whitespace from an
 * the given element. The function isBlock may optionally be passed in
 * to determine whether or not an element is a block element; if none
 * is provided, defaults to using the list of block elements provided
 * by the `block-elements` module.
 *
 * @param {Node} elem
 * @param {Function} blockTest
 */
declare function collapseWhitespace(elem: Node, isBlock?: Function, isPre?: Function): void;
export default collapseWhitespace;