/**
 * @typedef {import('hast').Nodes} Nodes
 */
/**
 * Get the rank (`1` to `6`) of headings (`h1` to `h6`).
 *
 * @param {Nodes} node
 *   Node to check.
 * @returns {number | undefined}
 *   Rank of the heading or `undefined` if not a heading.
 */
export function headingRank(node: Nodes): number | undefined;
export type Nodes = import('hast').Nodes;
