code: protected void onValidateSingleResult(List results)
      {
          if (results == null || results.isEmpty())
          {
              log.error("No result found for {} ", kunderaQuery.getJPAQuery());
              throw new NoResultException("No result found!");
          }
  
          if (results.size() > 1)
          {
              log.error("Non unique results found for query {} ", kunderaQuery.getJPAQuery());
              throw new NonUniqueResultException("Containing more than one result!");
          }
  
      }
docs: On validate single result.
  
  @param results
  the results