KEY__EXTRACOLUMNHEADERS__HEADER_TEXT: self._header_text,
KEY__EXTRACOLUMNHEADERS__IS_FILTERABLE: self._is_filterable,
KEY__EXTRACOLUMNHEADERS__IS_SORTABLE: self._is_sortable,
KEY__EXTRACOLUMNHEADERS__HEADER_TEXT: self._header_text,
KEY__EXTRACOLUMNHEADERS__IS_FILTERABLE: self._is_filterable,
KEY__EXTRACOLUMNHEADERS__IS_SORTABLE: self._is_sortable,