code: public BaseField getCodeField()
      {
          Record record = this.getOwner();
          if (m_iCodeField != null)
              return record.getField(m_iCodeField);
          else
              return record.getKeyArea(record.getCodeKeyArea()).getField(DBConstants.MAIN_KEY_FIELD);
      }
docs: Get the code field.
  @return The code field (or the index field if not found)