code: private static Sort getSort(String... columnNames) {
          Sort key = null;
          for (String s : columnNames) {
              if (key == null) {
                  key = first(s, Sort.Order.DESCEND);
              } else {
                  key.next(s, Sort.Order.DESCEND);
              }
          }
          return key;
      }
docs: Returns an object that can be used to sort this table in the order specified for by the given column names