@Transactional
 public Production modifie(Production aProduction, String nom, String logoUrl) {
   aProduction.setNom(nom);
   aProduction.setLogoUrl(logoUrl);
   em.persist(aProduction);
   return aProduction;
 }
 @Transactional
 public Production enregistrerNouveau(String nom, String logoUrl) {
   Production aProduction = new Production();
   aProduction.setNom(nom);
   aProduction.setLogoUrl(logoUrl);
   em.persist(aProduction);
   return aProduction;
 }