public static async Task InvokeAsync(IWorkflow workflow)
        {
            workflow = new Workflow();
            workflow.Add(new CallWebService(1));
            workflow.Add(new CallWebService(2));
            workflow.Add(new CallWebService(3));
            workflow.Add(new CallWebService(4));
            workflow.Add(new CallWebService(5));

            var engine = new WorkflowEngine();
            await engine.RunAsync(workflow);
        }
        public static void Invoke(IWorkflow workflow)
        {
            workflow = new Workflow();
            workflow.Add(new CallWebService(1));
            workflow.Add(new CallWebService(2));
            workflow.Add(new CallWebService(3));
            workflow.Add(new CallWebService(4));
            workflow.Add(new CallWebService(5));

            var engine = new WorkflowEngine();
            engine.Run(workflow);
        }