return BASE64;
  }

  private static final BaseEncoding BASE64_URL =
      new Base64Encoding(
          "base64Url()", "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_", '=');

  /**
   * The "base64url" encoding specified by <a
   * href="http://tools.ietf.org/html/rfc4648#section-5">RFC 4648 section 5</a>, Base 64 Encoding

  @AndroidIncompatible // Android forbids null parent ClassLoader
  public void testClassPathEntries_duplicateUri_parentWins() throws Exception {
    URL url = new URL("file:/a");
    URLClassLoader parent = new URLClassLoader(new URL[] {url}, null);
    URLClassLoader child = new URLClassLoader(new URL[] {url}, parent) {};
    assertThat(ClassPath.getClassPathEntries(child)).containsExactly(new File("/a"), parent);
  }

  @AndroidIncompatible // Android forbids null parent ClassLoader
  public void testClassPathEntries_duplicateUri_parentWins() throws Exception {
    URL url = new URL("file:/a");
    URLClassLoader parent = new URLClassLoader(new URL[] {url}, null);
    URLClassLoader child = new URLClassLoader(new URL[] {url}, parent) {};
    assertThat(ClassPath.getClassPathEntries(child)).containsExactly(new File("/a"), parent);
  }

    if (ip instanceof Inet6Address) {
      return "[" + toAddrString(ip) + "]";
    }
    return toAddrString(ip);
  }

  /**
   * Returns an InetAddress representing the literal IPv4 or IPv6 host portion of a URL, encoded in
   * the format specified by RFC 3986 section 3.2.2.
   *
   * <p>This method is similar to {@link InetAddresses#forString(String)}, however, it requires that
   * IPv6 addresses are surrounded by square brackets.

        return null;
      }
    }

    /** Gets URL for base of path containing Finalizer.class. */
    URL getBaseUrl() throws IOException {
      // Find URL pointing to Finalizer.class file.
      String finalizerPath = FINALIZER_CLASS_NAME.replace('.', '/') + ".class";
      URL finalizerUrl = getClass().getClassLoader().getResource(finalizerPath);
      if (finalizerUrl == null) {

        return null;
      }
    }

    /** Gets URL for base of path containing Finalizer.class. */
    URL getBaseUrl() throws IOException {
      // Find URL pointing to Finalizer.class file.
      String finalizerPath = FINALIZER_CLASS_NAME.replace('.', '/') + ".class";
      URL finalizerUrl = getClass().getClassLoader().getResource(finalizerPath);
      if (finalizerUrl == null) {

    public static final String ORIGIN_WHEN_CROSS_ORIGIN = "origin-when-cross-origin";
    public static final String STRICT_ORIGIN_WHEN_CROSS_ORIGIN = "strict-origin-when-cross-origin";
    public static final String UNSAFE_URL = "unsafe-url";
  }

  /**
   * The HTTP <a href="https://www.w3.org/TR/service-workers/#update-algorithm">{@code
   * Service-Worker}</a> header field name.
   *
   * @since 20.0
   */