Cancel commands

src/Core/FileTime.Core.Abstraction/Command/ICommand.cs

@@ -11,4 +11,5 @@ public interface ICommand
 
     Task<CanCommandRun> CanRun(PointInTime currentTime);
     Task<PointInTime> SimulateCommand(PointInTime currentTime);
+    void Cancel();
 }

src/Core/FileTime.Core.Abstraction/ContentAccess/IContentWriter.cs

@@ -4,6 +4,6 @@ public interface IContentWriter : IDisposable
 {
     int PreferredBufferSize { get; }
 
-    Task WriteBytesAsync(byte[] data, int? index = null);
-    Task FlushAsync();
+    Task WriteBytesAsync(byte[] data, int? index = null, CancellationToken cancellationToken = default);
+    Task FlushAsync(CancellationToken cancellationToken = default);
 }