@pveentjer we are not assuming that it will be done in 5 seconds.
we use sleep 6 seconds to give time for the TTL to expire.
then, the next map.get();  will fire the fireTtlCleanup() in a new Thread.
then, we use assertTrueEventually() as per normal, in the hope that the "ttlCleanup" will complete in ASSERT_TRUE_EVENTUALLY_TIMEOUT