/**
 * Comparator that allows sorting {@link Node} keys alphabetically
 * with the exception of "wordEnd" which should always come first.
 *
 * @param key1 - First key to compare.
 * @param key2 - Second key to compare.
 * @returns -1 if key1 should precede key2, 0 if they're the same, 1 if key2 should precede key1.
 */
export declare const nodeKeyComparator: (key1: string, key2: string) => number;