private static boolean isCheckerUrl(String url) {
        if ("http://c.validator.nu/all/".equals(url)
                || "http://hsivonen.iki.fi/checkers/all/".equals(url)) {
            return true;
        } else if ("http://c.validator.nu/base/".equals(url)) {
            return true;
        } else if ("http://c.validator.nu/rdfalite/".equals(url)) {
            return true;
        }
        for (String checker : ALL_CHECKERS) {
            if (checker.equals(url)) {
                return true;
            }
        }
        return false;
    }
@version $Id: VerifierServletTransaction.java,v 1.10 2005/07/24 07:32:48
         hsivonen Exp $
@author hsivonen
src/nu/validator/servlet/VerifierServletTransaction.java