'Tests resumable download that fails once and then completes,
with tracker file'

def test_failed_and_restarted_download_with_persistent_tracker(self):

    harness = CallbackTestHarness()
    tmpdir = self._MakeTempDir()
    tracker_file_name = self.make_tracker_file(tmpdir)
    dst_fp = self.make_dst_fp(tmpdir)
    (small_src_key_as_string, small_src_key) = self.make_small_key()
    res_download_handler = ResumableDownloadHandler(tracker_file_name=tracker_file_name, num_retries=1)
    small_src_key.get_contents_to_file(dst_fp, cb=harness.call, res_download_handler=res_download_handler)
    self.assertEqual(SMALL_KEY_SIZE, get_cur_file_size(dst_fp))
    self.assertEqual(small_src_key_as_string, small_src_key.get_contents_as_string())
    self.assertFalse(os.path.exists(tracker_file_name))
