This is a scenario that can lead a test failure:

1. A prepared transaction is recovered on stepUp, which acquires MODE_IX lock of a collection C
2. TTLMonitor starts collMod of C, which tries to acquire MODE_X lock and put to wait
3. test sends an insert command to C, which tries to acquire MODE_IX lock and put to wait.
4. The next commitTransaction command can't be issued because the test is single threaded and waits for cmd insert command to finish, thus the deadlock.