/// <summary>
 /// Atomically iterate through all key/value pairs in the map (in order) and execute an
 /// action on each
 /// </summary>
 /// <param name="action">Action to execute</param>
 /// <returns>Unit</returns>
 public static Unit iter <K, V>(HMap <K, V> map, Action <K, V> action) =>
 map.Iter(action);