public void SignalAsyncReturnsFaultedTaskOnError()
        {
            var evt = new AsyncCountdownEvent(0);

#pragma warning disable CS0618 // Type or member is obsolete
            var result = evt.SignalAsync();
#pragma warning restore CS0618 // Type or member is obsolete
            Assert.True(result.IsFaulted);
            Assert.IsType(typeof(InvalidOperationException), result.Exception.InnerException);
        }