code: @Override
  	final public long reportingGetLastModified(HttpServletRequest httpReq) throws IOException, SQLException {
  		WebSiteRequest req=getWebSiteRequest(httpReq);
  		Class<? extends WebPage> thisClass = getClass();
  		WebPage page=getWebPage(thisClass, req);
  
  		// Check authentication first
  		try {
  			WebSiteUser user=req.getWebSiteUser(null);
  			if(!page.canAccess(user)) return -1;
  		} catch(LoginException err) {
  			return -1;
  		}
  
  		// If redirected
  		if(page.getRedirectURL(req)!=null) return -1;
  
  		return page.getLastModified(req);
  	}
docs: First, resolves correct instance of <code>WebPage</code>.  Then, if security mode
  mismatches, authentication failed, or the page is a redirect, returns <code>-1</code>
  for unknown.  Otherwise, call <code>getLastModified(WebSiteRequest)</code>
  
  @see  #getLastModified(WebSiteRequest)