gistfile1.cs

    public delegate Task<R> Operation<T, R>(T t);
        
    public static partial class FuntionalExtensions
    {
        public static Operation<T, R> AddDebugLogging<T, R>(this Operation<T, R> @this) =>
            (T t) =>
                {
                    var result = @this(t);
                    Debug.WriteLine(result);
                    return result;
                };
    }