and tweak the methods in check.hxx to make them more flexible when
called with
   dc.Class(xxx ? "foo" : "bar")

Change-Id: I881fe628f22121ced4d8849715d6b1c92b092da1
Reviewed-on: https://gerrit.libreoffice.org/64207
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>