A more convenient way to write a saver when you want async

IAsyncSaver.cs

// New interface...

    using System.Threading.Tasks;

    public interface IAsyncSaver<T>
    {
        Task<T> Save(T item);
    }
    
// Old way...

    ISaver<Task<FileInfo>> saver = new AsyncFileSaver();
    FileInfo foo = new FileInfo("foo");
    // here we create a task for no reason other than to conform to 
    // the interface.
    FileInfo bar = await saver.Save(Task.FromResult(foo));
    
// New way...

    IAsyncSaver<FileInfo> saver = new AsyncFileSaver();
    FileInfo foo = new FileInfo("foo");
    FileInfo bar = await saver.Save(foo);