code: void set(Instant effectiveFrom, T value) {
  		T oldValue = get();
  		values.put(effectiveFrom, value);
  		notifyListeners(oldValue, value);
  	}
docs: Sets the value of the property at the specified time.
  
  For internal and test use only.<p/>
  Values are assumed to be set in chronological order.
  
  @param effectiveFrom
  @param value