library java.engine;

class StringUtilities {
  static List<String> EMPTY_ARRAY = new List(0);
}

class FileNameUtilities {
  static String getExtension(String fileName) {
    if (fileName == null) {
      return "";
    }
    int index = fileName.lastIndexOf('.');
    if (index >= 0) {
      return fileName.substring(index + 1);
    }
    return "";
  }
}