public function append($file, $content)
    {
        $stream = fopen('php://temp', 'r+');
        fwrite($stream, $content);
        rewind($stream);

        // prevent ftp_fput from seeking local "file" ($h)
        ftp_set_option($this->getConnection(), FTP_AUTOSEEK, false);

        $size = ftp_size($this->getConnection(), $file);
        $result = ftp_fput($this->getConnection(), $file, $stream, $this->transfer_mode, $size);
        fclose($stream);

        return $result;
    }