* Calls the static {@link #authenticate(HttpServletRequest,
     * HttpServletResponse, byte[])} method to perform NTLM authentication
     * for the specified servlet request.
     *
     * @param req The request being serviced.
     * @param resp The response.
     * @param challenge The domain controller challenge.
     * @throws IOException If an IO error occurs.
     * @throws ServletException If an error occurs.
     */

     * HttpServletResponse, byte[])} method to perform NTLM authentication
     * for the specified servlet request.
     * 
     * @param tc
     *
     * @param req
     *            The request being serviced.
     * @param resp
     *            The response.
     * @param challenge
     *            The domain controller challenge.
     * @return credentials passed in the servlet request
     * @throws IOException