Add support for exclusive mode

src/Spectre.Console.Testing/Fakes/FakeAnsiConsole.cs

@@ -9,12 +9,14 @@ namespace Spectre.Console.Testing
     {
         private readonly StringWriter _writer;
         private readonly IAnsiConsole _console;
+        private readonly FakeExclusivityMode _exclusivityLock;
 
         public string Output => _writer.ToString();
 
         public Profile Profile => _console.Profile;
         public IAnsiConsoleCursor Cursor => _console.Cursor;
         public FakeConsoleInput Input { get; }
+        public IExclusivityMode ExclusivityMode => _exclusivityLock;
         public RenderPipeline Pipeline => _console.Pipeline;
 
         IAnsiConsoleInput IAnsiConsole.Input => Input;
@@ -24,6 +26,7 @@ namespace Spectre.Console.Testing
             AnsiSupport ansi = AnsiSupport.Yes,
             int width = 80)
         {
+            _exclusivityLock = new FakeExclusivityMode();
             _writer = new StringWriter();
 
             var factory = new AnsiConsoleFactory();

src/Spectre.Console.Testing/Fakes/FakeConsole.cs

@@ -12,6 +12,7 @@ namespace Spectre.Console.Testing
         public Profile Profile { get; }
         public IAnsiConsoleCursor Cursor => new FakeAnsiConsoleCursor();
         IAnsiConsoleInput IAnsiConsole.Input => Input;
+        public IExclusivityMode ExclusivityMode { get; }
         public RenderPipeline Pipeline { get; }
 
         public FakeConsoleInput Input { get; }
@@ -24,6 +25,7 @@ namespace Spectre.Console.Testing
             bool legacyConsole = false, bool interactive = true)
         {
             Input = new FakeConsoleInput();
+            ExclusivityMode = new FakeExclusivityMode();
             Pipeline = new RenderPipeline();
 
             Profile = new Profile(new StringWriter(), encoding ?? Encoding.UTF8);

src/Spectre.Console.Testing/Fakes/FakeExclusivityMode.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Threading.Tasks;
+
+namespace Spectre.Console.Testing
+{
+    public sealed class FakeExclusivityMode : IExclusivityMode
+    {
+        public T Run<T>(Func<T> func)
+        {
+            return func();
+        }
+
+        public async Task<T> Run<T>(Func<Task<T>> func)
+        {
+            return await func();
+        }
+    }
+}