code: @Nullable
    public static String extractStringValue (@Nullable final String sStr)
    {
      if (StringHelper.hasNoText (sStr) || sStr.length () < 2)
        return sStr;
  
      final char cFirst = sStr.charAt (0);
      if ((cFirst == '"' || cFirst == '\'') && StringHelper.getLastChar (sStr) == cFirst)
      {
        // Remove quotes around the string
        return _trimBy (sStr, 1, 1);
      }
      return sStr;
    }
docs: Remove surrounding quotes (single or double) of a string (if present). If
  the start and the end quote are not equal, nothing happens.
  
  @param sStr
  The string where the quotes should be removed
  @return The string without quotes.