public static void Test_SubProcess_check_async()
        {
            SubProcess sp   = new SubProcess(echoArgs, "--exit", "2");
            Task       task = sp.CheckAsync();

            try
            {
                task.Wait();
                Assert.Fail("Did not throw on timeout");
            }
            catch (AggregateException ae)
            {
                Assert.AreEqual(1, ae.InnerExceptions.Count);
                Assert.IsTrue(ae.InnerExceptions[0] is SubProcess.Failed);
            }
        }