A delegate that is invoked by System.ServiceModel.ClientBase`1.InvokeAsync(System.ServiceModel.ClientBase.BeginOperationDelegate,System.Object[],System.ServiceModel.ClientBase.EndOperationDelegate,System.Threading.SendOrPostCallback,System.Object) on successful completion of the call made by System.ServiceModel.ClientBase`1.InvokeAsync(System.ServiceModel.ClientBase.BeginOperationDelegate,System.Object[],System.ServiceModel.ClientBase.EndOperationDelegate,System.Threading.SendOrPostCallback,System.Object) to System.ServiceModel.ClientBase`1.BeginOperationDelegate.