docs: private static Query buildQuery(ClassDescriptor cld)
      {
          FieldDescriptor[] pkFields = cld.getPkFields();
          Criteria crit = new Criteria();
  
          for(int i = 0; i < pkFields.length; i++)
          {
              crit.addEqualTo(pkFields[i].getAttributeName(), null);
          }
          return new QueryByCriteria(cld.getClassOfObject(), crit);
      }