private Validator combineValidatorByUrl(Validator val, String url)
            throws SAXException, IOException, IncorrectSchemaException {
        if (!"".equals(url)) {
            Validator v = validatorByUrl(url);
            if (val == null) {
                val = v;
            } else {
                val = new CombineValidator(v, val);
            }
        }
        return val;
    }
@param val
@param url
@return
@throws SAXException
@throws IOException
@throws IncorrectSchemaException
src/nu/validator/servlet/VerifierServletTransaction.java