docs: private static boolean isWhiteSpace(final char ch) {
          if (ch == CHAR_SPACE) return true;
          if (ch == CHAR_TAB) return true;
          if (ch == CHAR_NEW_LINE) return true;
          if (ch == CHAR_VERTICAL_TAB) return true;
          if (ch == CHAR_CARRIAGE_RETURN) return true;
          if (ch == CHAR_FORM_FEED) return true;
          return false;
      }