private void TestFillBufferWith(byte[] inputBuf)
        {
            byte[] outputBuf = new byte[inputBuf.Length];

            using (Stream s = new MemoryStream(inputBuf)) {
                Task.WaitAll(AsyncHelper.FillBuffer(s, outputBuf));
                CollectionAssert.AreEqual(inputBuf, outputBuf);
            }
        }