public async Task<PerformanceResourceTimingData2ApplicationPerformanceRow> TakeLastOne()
 {
     Console.WriteLine("enter TakeOne descending");
     var value = new PerformanceResourceTimingData2ApplicationPerformanceRow { Key = (PerformanceResourceTimingData2ApplicationPerformanceKey)13, z = new XElement("hello", "world") };
     Console.WriteLine("exit TakeOne descending " + new { value.Key });
     return value;
 }
        // https://sites.google.com/a/jsc-solutions.net/backlog/knowledge-base/2015/201510/20151025/testdatarowkey

        public void TakeLastOne(Action<PerformanceResourceTimingData2ApplicationPerformanceRow> yield)
        {
            Console.WriteLine("enter TakeOne descending");
            var value = new PerformanceResourceTimingData2ApplicationPerformanceRow { Key = (PerformanceResourceTimingData2ApplicationPerformanceKey)13, z = new XElement("hello", "world") };
            Console.WriteLine("exit TakeOne descending " + new { value.Key });
            yield(value);
        }