public void ClearTest()
        {
            var sequence = 0;
            var blocker  = new ManualResetEvent(false);
            var worker   = new WorkerQueue();

            worker.Queue(() => { Assert.AreEqual(0, sequence); blocker.WaitOne(); worker.Clear(); ++sequence; });
            worker.Queue(() => { Assert.AreEqual(1, sequence); ++sequence; });
            worker.Queue(() => { Assert.AreEqual(2, sequence); ++sequence; });
            worker.Queue(() => { Assert.AreEqual(3, sequence); ++sequence; });
            worker.Queue(() => { Assert.AreEqual(4, sequence); ++sequence; });
            worker.Queue(() => { Assert.AreEqual(5, sequence); ++sequence; });
            blocker.Set();
            Thread.Sleep(50);

            Assert.AreEqual(1, sequence);
        }