Inheritance: Message
 OperationResult OnUseActor(UseActor msg, IOperationContext context)
 {
     _actor = ActorProxy.Create<ISFTestActor>(new ActorId(msg.ActorName), new Uri("fabric:/SFActorsPerfTest/SFTestActorService"));
     return OperationResult.Success;
 }
 async Task<OperationResult> Process(UseActor msg, IOperationContext context)
 {
     _actor = await _actorSystem.GetActor(new ActorKey(msg.ActorName));
     return OperationResult.Success;
 }
 OperationResult OnUseActor(UseActor msg, IOperationContext context)
 {
     _actor = GrainClient.GrainFactory.GetGrain<ITestGrain>(msg.ActorName);
     return OperationResult.Success;
 }