/** Adds a new location to the list of configured locations. */
  private void addFile(File file) {
    file = file.getAbsoluteFile();

    if (pathFiles.contains(file)) {
      return;
    }

    if (classLoader != null) {
      try {
        classLoader.addURL(file.toURI().toURL());
      } catch (MalformedURLException ex) {
        return;
      }
    }

    pathFiles.add(file);
  }