System.Threading.Tasks.Task GrainInterfaces.ISystemGrain.Unsubscribe(GrainInterfaces.ISystemObserver @observer) { global::Orleans.CodeGeneration.GrainFactoryBase.CheckGrainObserverParamInternal(@observer); return base.InvokeMethodAsync<object>(-1645784438, new object[] {@observer is global::Orleans.Grain ? @observer.AsReference<GrainInterfaces.ISystemObserver>() : @observer} ); }