domain class + key concode_field_sep KeyColumn<U,T> column concode_elem_sep long serialVersionUID concode_field_sep KeyRing<U> getSortProperty concode_elem_sep IModel<String> getDisplayModel concode_elem_sep void populateItem concode_elem_sep boolean isSortable concode_elem_sep void detach concode_elem_sep T getDataValue concode_elem_sep IModel<T> getDataModel concode_elem_sep Component getHeader
String function ( ) { return column . toString ( ) ; }