Currently, for updating lastDurable and lastApplied timestamp in ReplicationCoordinator, we have four functions:

• setMyLastAppliedOpTimeAndWallTimeForward -> Used by OplogApplier
• setMyLastDurableOpTimeAndWallTimeForward -> Used by ReplicationCoordinatorExternalState::onDurable
• setMyLastAppliedOpTimeAndWallTime -> Not used at all
• setMyLastDurableOpTimeAndWallTime -> We can use setMyLastDurableOpTimeAndWallTimeForward instead if this comment is true.

We can cleanup the interfaces to only keep one function for updating lastApplied and lastDurable respectively.