and then throw an exception when the interface is used

Change-Id: Id5e2c852323d49f51ab55cf46ab54223cf8ccf03
Reviewed-on: https://gerrit.libreoffice.org/9590Reviewed-by: Lionel Elie Mamane <lionel@mamane.lu>
Tested-by: Lionel Elie Mamane <lionel@mamane.lu>