public Float getSumOfHoursByCommandes(CommandesEntity commandesEntity) {
   Float res = 0.f;
   for (HistoriqueHeuresEntity historiqueHeuresEntity :
       commandesEntity.getHistoriqueHeuresesByCommandId()) {
     res += historiqueHeuresEntity.getHistoriqueHeures();
   }
   return res;
 }
 public CommandesEntity removeHistoriqueHeuresToCommandes(
     HistoriqueHeuresEntity historiqueHeuresEntity, CommandesEntity commandesEntity) {
   commandesEntity.getHistoriqueHeuresesByCommandId().remove(historiqueHeuresEntity);
   dao.makePersistent(commandesEntity);
   return commandesEntity;
 }