In other methods it's always checked, so presumably it might be absent.
In caller sites (like OOXMLFastContextHandler::endOfParagraph), it can't
(and shouldn't) be checked.

Change-Id: Ia2edf8b121cac15e6454bc6321d76517fcdf110f
Reviewed-on: https://gerrit.libreoffice.org/45951Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>