docs: public void init(Record record, DateTimeField field, String mainFilesFieldName)
      {
          super.init(record);
          m_field = field;
          if (field != null)
              if (field.getRecord() != record)
                  field.addListener(new FieldRemoveBOnCloseHandler(this));
          this.mainFilesFieldName = mainFilesFieldName;
      }