* Observer download notification.
*/
private void notifyDownload(final FtpIoSession session, final FileObject file, final long size) {
StatisticsObserver observer = this.observer;
if (observer != null) {
observer.notifyDownload();
}
FileObserver fileObserver = this.fileObserver;
if (fileObserver != null) {
fileObserver.notifyDownload(session, file, size);