This is only called from one place inside the class itself.
Move the logic there (which also avoids the need for a
const_cast) and transfer the part of the comments that
(still) applies and update them. Drop the rest.
Change-Id: I39ab040a6a13f9483773ade99f30abd959ead6f2
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/206018
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
Tested-by: Jenkins