import type { IsoDuration } from '../../domain.objects/IsoDuration';
/**
 * .what = stringify an IsoDuration into short human words
 * .why  = minimum-surface-area: one obvious input, safe defaults
 * .how  =
 *   - order: years → ms
 *   - skip zeros
 *   - max 2 nonzero units
 *   - compact labels (e.g. 2h 5m)
 *   - fallback "0s" when all zero
 */
export declare const asDurationInWords: (duration: IsoDuration) => string;