private static boolean containsWhitespacesOnly(@NotNull CharSequence chars, int start, int end) {
      for (int i = start; i < end; i++) {
        final char c = chars.charAt(i);
        if (c == ' ' || c == '\t' || c == '\n' || c == '\r') continue;
        return false;
      }
      return true;
    }
private static boolean containsWhitespacesOnly(@NotNull CharSequence chars, int start, int end)