/**
 * Calculate the distance in Km
 * Sourced from StackOverflow (https://stackoverflow.com/questions/27928/calculate-distance-between-two-latitude-longitude-points-haversine-formula)
 * This is the 'fastest' algorithm apparently
 *
 * @param lat1
 * @param lon1
 * @param lat2
 * @param lon2
 * @returns number The distance in km
 */
export declare const getDistanceFromLatLonInKm: (lat1: number, lon1: number, lat2: number, lon2: number) => number;