public LifeDatesWrapper(Model.LifeSpan lifeDates)
 {
     if (lifeDates == null) {
         throw new ArgumentNullException("LifeDates must not be null");
     }
     _lifeDates = lifeDates;
 }
 public LifeDatesWrapper(Model.LifeSpan lifeDates)
 {
     if (lifeDates == null)
     {
         throw new ArgumentNullException("LifeDates must not be null");
     }
     _lifeDates = lifeDates;
 }