`blobovniczatree` takes a really long time to prefill, because each
batch takes at least 10ms, so for 10k iterations we have at least 100s of
prefill.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
I tried to add 4 more tests and suddenly, it became harder to navigate in
code. Move directory creation in a common function.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
