}

  /**
   * Returns the URLs in the class path specified by the {@code java.class.path} {@linkplain
   * System#getProperty system property}.
   */
  // TODO(b/65488446): Make this a public API.
  @J2ktIncompatible
  @GwtIncompatible
  private static ImmutableList<URL> parseJavaClassPath() {
    ImmutableList.Builder<URL> urls = ImmutableList.builder();

 * <td>A-Z a-z 0-9 + /
 * <td>1.33
 * <td>=
 * <td>
 * <tr>
 * <td>{@link #base64Url()}
 * <td>A-Z a-z 0-9 - _
 * <td>1.33
 * <td>=
 * <td>Safe to use as filenames, or to pass in URLs without escaping
 * </table>
 *
 * <p>All instances of this class are immutable, so they may be stored safely as static constants.
 *
 * @author Louis Wasserman
 * @since 14.0
 */

    assertNotNull(FinalizableReferenceQueue.getStartFinalizer(finalizerCopy));
  }

  static class DecoupledClassLoader extends URLClassLoader {

    public DecoupledClassLoader(URL[] urls) {
      super(urls);
    }

    @Override
    protected synchronized Class<?> loadClass(String name, boolean resolve)
        throws ClassNotFoundException {

    assertNotNull(FinalizableReferenceQueue.getStartFinalizer(finalizerCopy));
  }

  static class DecoupledClassLoader extends URLClassLoader {

    public DecoupledClassLoader(URL[] urls) {
      super(urls);
    }

    @Override
    protected synchronized Class<?> loadClass(String name, boolean resolve)
        throws ClassNotFoundException {

    try {
      ImmutableList<URL> urls = ClassPath.parseJavaClassPath();

      assertThat(urls.get(0).getProtocol()).isEqualTo("file");
      assertThat(urls.get(0).getAuthority()).isNull();
      assertThat(urls.get(0).getPath()).endsWith("/relative/path/to/some.jar");

      assertThat(urls.get(1)).isEqualTo(new URL("file:///absolute/path/to/some.jar"));

      assertThat(urls.get(2).getProtocol()).isEqualTo("file");

    try {
      ImmutableList<URL> urls = ClassPath.parseJavaClassPath();

      assertThat(urls.get(0).getProtocol()).isEqualTo("file");
      assertThat(urls.get(0).getAuthority()).isNull();
      assertThat(urls.get(0).getPath()).endsWith("/relative/path/to/some.jar");

      assertThat(urls.get(1)).isEqualTo(new URL("file:///absolute/path/to/some.jar"));

      assertThat(urls.get(2).getProtocol()).isEqualTo("file");

      } catch (Exception ignore) {
        // probably URISyntaxException or IllegalArgumentException
        // fall back to copying URLs to files in the testDir == null block below
      }
    }

    if (testDir == null) {
      // testdata resources aren't file:// urls, so create a directory to store them in and then
      // copy the resources to the filesystem as needed
      testDir = createTempDir();
    }

  }

  /**
   * Returns the URLs in the class path specified by the {@code java.class.path} {@linkplain
   * System#getProperty system property}.
   */
  // TODO(b/65488446): Make this a public API.
  @J2ktIncompatible
  @GwtIncompatible
  private static ImmutableList<URL> parseJavaClassPath() {
    ImmutableList.Builder<URL> urls = ImmutableList.builder();

      } catch (Exception ignore) {
        // probably URISyntaxException or IllegalArgumentException
        // fall back to copying URLs to files in the testDir == null block below
      }
    }

    if (testDir == null) {
      // testdata resources aren't file:// urls, so create a directory to store them in and then
      // copy the resources to the filesystem as needed
      testDir = createTempDir();
    }