@Override
 public Authorization createAuthorization(String id, String accountId, String hwInstanceId) {
   if (repo.accountExists(accountId) && repo.hwInstanceExists(hwInstanceId)) {
     Authorization authorization = new Authorization(id, accountId, hwInstanceId);
     repo.addAuthorization(authorization);
     return authorization;
   } else {
     return null;
   }
 }
 @Override
 public boolean authorizationExists(String accountId, String hwInstanceId) {
   return repo.authorizationExists(accountId, hwInstanceId);
 }
 @Override
 public boolean authorizationExists(String id) {
   return repo.authorizationExists(id);
 }
 @Override
 public void destroyAuthorization(String id) {
   repo.deleteAuthorization(id);
 }
 @Override
 public Authorization getAuthorization(String authorizationId) {
   return repo.getAuthorization(authorizationId);
 }
 @Override
 public List<Authorization> getAllAuthorizations() {
   return repo.getAuthorizations();
 }