public static async Task Bind_NullTask(Func <string, Task <int> > binder)
        {
            var actual = await Record.ExceptionAsync(() => TaskExtensions.Bind(null, binder))
                         .ConfigureAwait(false);

            var ane = Assert.IsType <ArgumentNullException>(actual);

            Assert.Contains("taskValue", ane.Message, Ordinal);
        }