protected Iterator<String> keysImpl() {
   //noinspection unchecked
   Enumeration<String> names = request.getParameterNames();
   return names == null ? null : CollectionUtil.iterator(names);
 }
 protected Iterator<String> valuesImpl(String pName) {
   String[] values = request.getParameterValues(pName);
   return values == null ? null : CollectionUtil.iterator(values);
 }