T result = operation.get();
                long responseTime = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startTime);
                onSuccess(responseTime);
                return result;
            } catch (Exception e) {
                long responseTime = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startTime);
                onFailure(e, responseTime);
                if (e instanceof CIFSException) {

     */
    class LargeResponseMockHttpURLConnection extends HttpURLConnection {
        private final int responseSize;

        LargeResponseMockHttpURLConnection(URL u, int responseSize) {
            super(u);
            this.responseSize = responseSize;
        }

        @Override
        public void disconnect() {
        }

        @Override