The getTTCoverage either leaves the bitset empty or inits it with 128 bits,
so it's not particularly dynamic.

Change-Id: Iac0aa6a023acc54da86d681e75ca550faf91ef26
Reviewed-on: https://gerrit.libreoffice.org/25456Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>