Base class for EventArgs
Inheritance: System.EventArgs
        private void OnStarted(object sender, ProgressEventArgs e)
        {
            AssertEventHandlerArgsNotNull(sender, e);

            this.started = true;
            // Satisfy the sequential controller verification code
            e.Handled();
        }
 private void ControllerStarted(object sender, ProgressEventArgs e)
 {
     // Show can be modal and block, so begin invoke it
     VsThreadingHelper.BeginTask(this.serviceProvider, VsTaskRunContext.UIThreadNormalPriority,
         this.host.Show);
     // Flag that handled to assist with the verification, otherwise the controller will assert
     e.Handled();
 }
        private void OnStarted()
        {
            this.IsStarted = true;
            this.ThreadSafeCreateCancellationTokenSource();

            VsThreadingHelper.RunInline(this, VsTaskRunContext.UIThreadNormalPriority, () =>
            {
                ConfigureStepEventListeners(true);

                var delegates = this.StartedPrivate;
                if (delegates != null)
                {
                    ProgressEventArgs args = new ProgressEventArgs();
                    delegates(this, args);
                    // Verify that the observer handled it since now easy way of testing
                    // serialized raising and handling of the event across the classes
                    args.CheckHandled();
                }
            });
        }