Calls that get forwarded to the Driver itself. For example ::InitializeSimulationState(FSyncState*, FAuxState*). We can't provide a generic implementation because the state type is defined by the user. We forward this to the Driver because that is ultimately where the initial simulation state is seeded from. Defining InitializeSimulationState on the Driver itself is the simplest way of doing this and will make the most sense to anyone looking at the Driver class.