try {
        // 1.8, 9, 10, 11, 12 etc
        val version = jvmVersion.toInt()
        if (version >= 9) return null
      } catch (_: NumberFormatException) {
        // expected on >= JDK 9
      }

      // Find Jetty's ALPN extension for OpenJDK.
      try {
        val alpnClassName = "org.eclipse.jetty.alpn.ALPN"
        val alpnClass = Class.forName(alpnClassName, true, null)

  @GwtIncompatible // NullPointerTester
  public void testNulls() throws NoSuchMethodException {
    NullPointerTester tester = new NullPointerTester();
    // Necessary until JDK15:
    // https://bugs.openjdk.org/browse/JDK-8202469
    tester.ignore(Equivalence.class.getMethod("wrap", Object.class));

    tester.testAllPublicStaticMethods(Equivalence.class);
    tester.testAllPublicInstanceMethods(Equivalence.equals());

  protected static String formatFeatureSet(Set<? extends Feature<?>> features) {
    List<String> temp = new ArrayList<>();
    for (Feature<?> feature : features) {
      Object featureAsObject = feature; // to work around bogus JDK warning
      if (featureAsObject instanceof Enum) {
        Enum<?> f = (Enum<?>) featureAsObject;
        temp.add(f.getDeclaringClass().getSimpleName() + "." + feature);
      } else {

  private static final int GREATEST = Integer.MAX_VALUE;

  private static final int[] VALUES = {LEAST, (int) -1, (int) 0, (int) 1, GREATEST};

  // We need to test that our method behaves like the JDK method.
  @SuppressWarnings("InlineMeInliner")
  public void testHashCode() {
    for (int value : VALUES) {
      assertThat(Ints.hashCode(value)).isEqualTo(Integer.hashCode(value));
    }
  }

        for (Annotation a : classOrMethod.getDeclaredAnnotations()) {
          /*
           * We avoid reflecting on NullMarked because its @Target(..., MODULE) causes problems
           * under JDK 8.
           */
          if (!(a instanceof NullMarked)
              && a.annotationType().isAnnotationPresent(TesterAnnotation.class)) {
            annotations.add(a);
          }
        }

 * here. Cipher suites that are not available on either Android (through API level 24) or Java
 * (through JDK 9) are omitted for brevity.
 *
 * See [Android SSLEngine][sslengine] which lists the cipher suites supported by Android.
 *
 * See [JDK Providers][oracle_providers] which lists the cipher suites supported by Oracle.
 *

    // TODO(lukes): assert that the logs are full of errors
  }

  /**
   * Runs the corresponding {@link FuturesTest} test method in a new classloader that disallows
   * certain core JDK classes.
   */
  private void runTestMethod(ClassLoader classLoader) throws Exception {
    ClassLoader oldClassLoader = Thread.currentThread().getContextClassLoader();

   * application class loader.
   *
   * NOTE: The tests for this behavior (FinalizableReferenceQueueClassLoaderUnloadingTest) fail
   * strangely when run in JDK 9. We are considering this a known issue. Please see
   * https://github.com/google/guava/issues/3086 for more information.
   */

   * other utilities in this package.
   *
   * <p><b>Note:</b> this method simply delegates to the JDK method {@link Float#compare}. It is
   * provided for consistency with the other primitive types, whose compare methods were not added
   * to the JDK until JDK 7.
   *
   * @param a the first {@code float} to compare
   * @param b the second {@code float} to compare

 * finalization to happen. However, a call to {@code System.gc()} is specified to be no more than a
 * hint, so this technique may fail at the whim of the JDK implementation, for example if a user
 * specified the JVM flag {@code -XX:+DisableExplicitGC}. But in practice, it works very well for
 * ordinary tests.
 *