The _XSpreadsheetDocument test is already written in C++ since commit
b9337e22.

Change-Id: Icc0fc266f6e375ceb94edd5a95d396540972a908
Reviewed-on: https://gerrit.libreoffice.org/41409Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>