function addFile($src, $dest)
    {
        $dataPref = 'data' . DIRECTORY_SEPARATOR;
        $prefLen = strlen($dataPref);
        if ((strncasecmp($dest, $dataPref, $prefLen) != 0)
            && (strncasecmp($dest, $dataPref, $prefLen) != 0)
        ) {
            $dest = $dataPref . $dest;
        }

        $fulldest = "{$this->bagDirectory}/$dest";
        $dirname = dirname($fulldest);
        if (! is_dir($dirname)) {
            mkdir($dirname, 0777, true);
        }

        copy($src, $fulldest);
    }