System.setProperty(PATH_SEPARATOR.key(), oldPathSeparator);
      System.setProperty(JAVA_CLASS_PATH.key(), oldClassPath);
    }
  }

  private static boolean contentEquals(URL left, URL right) throws IOException {
    return Resources.asByteSource(left).contentEquals(Resources.asByteSource(right));
  }

  private static class Nested {}


  public void testNulls() throws IOException {

static String[] getFilesFromExtensio(String, String[]); private static java.util.Vector blendFilesToVector(java.util.Vector, String[]); private static boolean isValidFile(String, String[]); public static void mkdir(String); public static boolean contentEquals(java.io.File, java.io.File) throws java.io.IOException; public static java.io.File toFile(java.net.URL); public static java.net.URL[] toURLs(java.io.File[]) throws java.io.IOException; public static String removeExtension(String); public static...