in src/main/java/org/apache/sling/launchpad/testservices/filters/TestFilter.java [38:48]
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
String header = getHeaderName();
AtomicInteger current = (AtomicInteger) ((HttpServletRequest)request).getAttribute(header);
if (current == null) {
current = new AtomicInteger(0);
((HttpServletRequest)request).setAttribute(header, current);
}
((HttpServletResponse) response).setHeader(header, String.valueOf(current.incrementAndGet()));
chain.doFilter(request, response);
}