//[/GenericReduceSumInts]

        //[GenericReduceSumDoubles]
        public static void SumDoubles()
        {
            foreach (var n in Nums)
            {
                var values = Gen(Rng.NextDouble, n);
                var dr     = ReduceApi.Sum(values);
                var hr     = cpuReduce((x, y) => x + y, values);
                Assert.AreEqual(hr, dr, 1e-11);
            }
        }