char padChar = paddingChar.charValue();
      int l;
      for (l = chars.length() - 1; l >= 0; l--) {
        if (chars.charAt(l) != padChar) {
          break;
        }
      }
      return chars.subSequence(0, l + 1);
    }

    @Override
    public boolean canDecode(CharSequence chars) {
      checkNotNull(chars);
      chars = trimTrailingPadding(chars);