chore: import upstream snapshot with attribution

dotnet/samples/01-get-started/05_first_workflow/Program.cs

@@ -0,0 +1,63 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.Workflows;
+
+namespace WorkflowExecutorsAndEdgesSample;
+
+/// <summary>
+/// This sample introduces the concepts of executors and edges in a workflow.
+///
+/// Workflows are built from executors (processing units) connected by edges (data flow paths).
+/// In this example, we create a simple text processing pipeline that:
+/// 1. Takes input text and converts it to uppercase using an UppercaseExecutor
+/// 2. Takes the uppercase text and reverses it using a ReverseTextExecutor
+///
+/// The executors are connected sequentially, so data flows from one to the next in order.
+/// For input "Hello, World!", the workflow produces "!DLROW ,OLLEH".
+/// </summary>
+public static class Program
+{
+    private static async Task Main()
+    {
+        // Create the executors
+        Func<string, string> uppercaseFunc = s => s.ToUpperInvariant();
+        var uppercase = uppercaseFunc.BindAsExecutor("UppercaseExecutor");
+
+        ReverseTextExecutor reverse = new();
+
+        // Build the workflow by connecting executors sequentially
+        WorkflowBuilder builder = new(uppercase);
+        builder.AddEdge(uppercase, reverse).WithOutputFrom(reverse);
+        var workflow = builder.Build();
+
+        // Execute the workflow with input data
+        await using Run run = await InProcessExecution.RunAsync(workflow, "Hello, World!");
+        foreach (WorkflowEvent evt in run.NewEvents)
+        {
+            if (evt is ExecutorCompletedEvent executorComplete)
+            {
+                Console.WriteLine($"{executorComplete.ExecutorId}: {executorComplete.Data}");
+            }
+        }
+    }
+}
+
+/// <summary>
+/// Second executor: reverses the input text and completes the workflow.
+/// </summary>
+internal sealed class ReverseTextExecutor() : Executor<string, string>("ReverseTextExecutor")
+{
+    /// <summary>
+    /// Processes the input message by reversing the text.
+    /// </summary>
+    /// <param name="message">The input text to reverse</param>
+    /// <param name="context">Workflow context for accessing workflow services and adding events</param>
+    /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests.
+    /// The default is <see cref="CancellationToken.None"/>.</param>
+    /// <returns>The input text reversed</returns>
+    public override ValueTask<string> HandleAsync(string message, IWorkflowContext context, CancellationToken cancellationToken = default)
+    {
+        // Because we do not suppress it, the returned result will be yielded as an output from this executor.
+        return ValueTask.FromResult(string.Concat(message.Reverse()));
+    }
+}