} catch (NullPointerException expected) {
      // pass
    }
  }

  /**
   * Tests that specifying any alphanumeric characters as 'safe' causes an {@link
   * IllegalArgumentException}.
   */
  public void testBadArguments_badchars() {
    String msg =
        "Alphanumeric characters are always 'safe' " + "and should not be explicitly specified";
    try {
      new PercentEscaper("-+#abc.!", false);