import { Feature, Polygon, MultiPolygon, Properties } from "@turf/helpers";
/**
 * Takes two {@link (Multi)Polygon(s)} and returns a combined polygon. If the input polygons are not contiguous, this function returns a {@link MultiPolygon} feature.
 *
 * @name union
 * @param {Feature<Polygon|MultiPolygon>} polygon1 input Polygon feature
 * @param {Feature<Polygon|MultiPolygon>} polygon2 Polygon feature to difference from polygon1
 * @param {Object} [options={}] Optional Parameters
 * @param {Object} [options.properties={}] Translate Properties to output Feature
 * @returns {Feature<(Polygon|MultiPolygon)>} a combined {@link Polygon} or {@link MultiPolygon} feature, or null if the inputs are empty
 * @example
 * var poly1 = turf.polygon([[
 *     [-82.574787, 35.594087],
 *     [-82.574787, 35.615581],
 *     [-82.545261, 35.615581],
 *     [-82.545261, 35.594087],
 *     [-82.574787, 35.594087]
 * ]], {"fill": "#0f0"});
 * var poly2 = turf.polygon([[
 *     [-82.560024, 35.585153],
 *     [-82.560024, 35.602602],
 *     [-82.52964, 35.602602],
 *     [-82.52964, 35.585153],
 *     [-82.560024, 35.585153]
 * ]], {"fill": "#00f"});
 *
 * var union = turf.union(poly1, poly2);
 *
 * //addToMap
 * var addToMap = [poly1, poly2, union];
 */
declare function union<P = Properties>(poly1: Feature<Polygon | MultiPolygon> | Polygon | MultiPolygon, poly2: Feature<Polygon | MultiPolygon> | Polygon | MultiPolygon, options?: {
    properties?: P;
}): Feature<Polygon | MultiPolygon, P> | null;
export default union;
