static CallbackHandler()
 {
     etDelegate  = new GetElapsedTimeDelegate(GetElapsedTime);
     logDelegate = new LogMessageDelegate(LogMessage);
 }
        private static extern IntPtr ManagedSystemInterface_Create(GetElapsedTimeDelegate etDelegate, LogMessageDelegate logDelegate
#if FULL_AOT_COMPILE
                                                                   , IntPtr instanceHandle
#endif
                                                                   );