docs: @Nullable
    public static String javaScriptEscapeForRegEx (@Nullable final String sInput)
    {
      if (StringHelper.hasNoText (sInput))
        return sInput;
  
      final char [] aInput = sInput.toCharArray ();
      if (!StringHelper.containsAny (aInput, CHARS_TO_MASK_REGEX))
        return sInput;
  
      // At last each character has one masking character
      final char [] ret = new char [aInput.length * 2];
      int nIndex = 0;
      for (final char cCurrent : aInput)
        if (ArrayHelper.contains (CHARS_TO_MASK_REGEX, cCurrent))
        {
          ret[nIndex++] = MASK_CHAR_REGEX;
          ret[nIndex++] = cCurrent;
        }
        else
          ret[nIndex++] = cCurrent;
  
      return new String (ret, 0, nIndex);
    }