public async Task DownloadWithProgressCancelTest()
{
var testFileContent = Enumerable.Range(1, 1000).Select(i => (byte)(i & 255)).ToArray();
var testFile = await Amazon.Files.UploadNew(TestDirId, testFileName, () => new MemoryStream(testFileContent));
var memStr = new MemoryStream();
await Assert.ThrowsAsync<OperationCanceledException>(async () =>
await Amazon.Files.Download(testFile.id, memStr, bufferSize: 10, progress: ProgressCancel));
Assert.Equal(10, memStr.Position);
}