Consider the following operations ordering:
1. Inhume(with tombstone A) --> add tombstone mark for an object
2. --> new epoch arives
3. --> GCMark is added for a tombstone A, because it is unavailable
4. Put(A) --> return error, because the object already has a GCMark
It is possible, and I have successfully reproduced it with a test on the
shard level. However, the error is related to the specific
_ordering_ of operations with engine. And triggering race-conditions like
this is only possible on a shard level currently, so no tests are
written.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>