/// <summary>
 /// Indexer to get a registered Measures instance.
 /// <exception cref="ArgumentOutOfRangeException"></exception>.
 /// </summary>
 public U_meas this[MeasuresStore id]
 {
     get
     {
         return(_measuresStore[id]);
     }
 }
 /// <summary>
 /// Register a measure.
 /// </summary>
 /// <param name="measure"></param>
 public void RegisterMeasure(MeasuresStore id, U_meas measure)
 {
     _measuresStore.Add(id, measure);
     _measuresList.Add(measure);
 }
 /// <summary>
 /// Try to get a Measures instance from its id.\n
 /// NOTE: Use this method to avoid exception when you know you want to handle null ref in case
 /// you explicitly not registered any Measures (due to an external activation bool flag).
 /// </summary>
 /// <code>measuresAggreg.TryGet(MeasuresStore.Slot1)?.AddMeasure(myVal)</code>
 /// <param name="id">The identifier of the registered Measures instance.</param>
 /// <returns>Measures instance if exist or null otherwise.</returns>
 public U_meas TryGet(MeasuresStore id)
 {
     return(_measuresStore.ContainsKey(id) ? _measuresStore[id] : null);
 }