}

    /**
     * This method simply calls {@code negotiate( req, resp, false )}
     * and then {@code chain.doFilter}. You can override and call
     * negotiate manually to achive a variety of different behavior.
     */
    @Override
    public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain)
            throws IOException, ServletException {

            response.getWriter().write("Complex response");
            chain.doFilter(request, response);
        }
    }

    // Test helper classes

    private static class TestFilterChain implements FilterChain {
        private boolean doFilterCalled = false;

        @Override
        public void doFilter(ServletRequest request, ServletResponse response) throws IOException, ServletException {