docs: private FieldDescriptor extractIdentityColumnField(ClassDescriptor cld)
      {
          FieldDescriptor[] pkFields = cld.getPkFields();
          for(int i = 0; i < pkFields.length; i++)
          {
              // to find the identity column we search for a autoincrement
              // read-only field
              if(pkFields[i].isAutoIncrement() && pkFields[i].isAccessReadOnly())
              {
                  return pkFields[i];
              }
          }
          return null;
      }