Make KernelFunctionNoop internal

dotnet/src/Agents/Core/ChatCompletionAgent.cs

@@ -88,12 +88,10 @@ protected override Task<AgentChannel> RestoreChannelAsync(string channelState, C
 
     internal static (IChatCompletionService service, PromptExecutionSettings? executionSettings) GetChatCompletionService(Kernel kernel, KernelArguments? arguments)
     {
-        // Need to provide a KernelFunction to the service selector as a container for the execution-settings.
-        KernelFunction nullPrompt = new KernelFunctionNoop(arguments?.ExecutionSettings);
         (IChatCompletionService chatCompletionService, PromptExecutionSettings? executionSettings) =
             kernel.ServiceSelector.SelectAIService<IChatCompletionService>(
                 kernel,
-                nullPrompt,
+                arguments?.ExecutionSettings,
                 arguments ?? []);
 
         return (chatCompletionService, executionSettings);

dotnet/src/SemanticKernel.Abstractions/Functions/KernelFunctionNoop.cs

@@ -14,13 +14,13 @@ namespace Microsoft.SemanticKernel;
 /// </summary>
 [RequiresUnreferencedCode("Uses reflection to handle various aspects of the function creation and invocation, making it incompatible with AOT scenarios.")]
 [RequiresDynamicCode("Uses reflection to handle various aspects of the function creation and invocation, making it incompatible with AOT scenarios.")]
-public sealed class KernelFunctionNoop : KernelFunction
+internal sealed class KernelFunctionNoop : KernelFunction
 {
     /// <summary>
     /// Creates a new instance of the <see cref="KernelFunctionNoop"/> class.
     /// </summary>
     /// <param name="executionSettings">Option: Prompt execution settings.</param>
-    public KernelFunctionNoop(IReadOnlyDictionary<string, PromptExecutionSettings>? executionSettings) :
+    internal KernelFunctionNoop(IReadOnlyDictionary<string, PromptExecutionSettings>? executionSettings) :
         base($"Function_{Guid.NewGuid():N}", string.Empty, [], null, executionSettings?.ToDictionary(static kv => kv.Key, static kv => kv.Value))
     {
     }

dotnet/src/SemanticKernel.Abstractions/Services/AIServiceExtensions.cs

@@ -2,6 +2,8 @@
 
 #pragma warning disable CA1716 // Identifiers should not match keywords
 
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Text;
 using Microsoft.Extensions.DependencyInjection;
@@ -109,4 +111,32 @@ public static (T, PromptExecutionSettings?) SelectAIService<T>(
 
         throw new KernelException(message.ToString());
     }
+
+    /// <summary>
+    /// Resolves an <see cref="IAIService"/> and associated <see cref="PromptExecutionSettings"/> from the specified
+    /// <see cref="Kernel"/> based on a <see cref="KernelFunction"/> and associated <see cref="KernelArguments"/>.
+    /// </summary>
+    /// <typeparam name="T">
+    /// Specifies the type of the <see cref="IAIService"/> required. This must be the same type
+    /// with which the service was registered in the <see cref="IServiceCollection"/> orvia
+    /// the <see cref="IKernelBuilder"/>.
+    /// </typeparam>
+    /// <param name="selector">The <see cref="IAIServiceSelector"/> to use to select a service from the <see cref="Kernel"/>.</param>
+    /// <param name="kernel">The <see cref="Kernel"/> containing services, plugins, and other state for use throughout the operation.</param>
+    /// <param name="executionSettings">The dictionary of <see cref="PromptExecutionSettings"/> to use to select a service from the <see cref="Kernel"/>.</param>
+    /// <param name="arguments">The function arguments.</param>
+    /// <returns>A tuple of the selected service and the settings associated with the service (the settings may be null).</returns>
+    /// <exception cref="KernelException">An appropriate service could not be found.</exception>
+    [RequiresUnreferencedCode("Uses reflection to handle various aspects of the function creation and invocation, making it incompatible with AOT scenarios.")]
+    [RequiresDynamicCode("Uses reflection to handle various aspects of the function creation and invocation, making it incompatible with AOT scenarios.")]
+    public static (T, PromptExecutionSettings?) SelectAIService<T>(
+        this IAIServiceSelector selector,
+        Kernel kernel,
+        IReadOnlyDictionary<string, PromptExecutionSettings>? executionSettings,
+        KernelArguments arguments) where T : class, IAIService
+    {
+        // Need to provide a KernelFunction to the service selector as a container for the execution-settings.
+        KernelFunction nullPrompt = new KernelFunctionNoop(executionSettings);
+        return selector.SelectAIService<T>(kernel, nullPrompt, arguments);
+    }
 }