@Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
            throws ServletException, IOException {
        
        response.setHeader(CONTENT_SECURITY_POLICY_HEADER, CONTENT_SECURITY_POLICY);
        filterChain.doFilter(request, response);
    }
@Test
    void testSetResponseHeader() throws ServletException, IOException {
        XssFilter xssFilter = new XssFilter();
        xssFilter.doFilterInternal(request, response, filterChain);
        Mockito.verify(response).setHeader(CONTENT_SECURITY_POLICY_HEADER, CONTENT_SECURITY_POLICY);
    }