private static final char GREATEST = Character.MAX_VALUE;

  private static final char[] VALUES = {LEAST, 'a', '\u00e0', '\udcaa', GREATEST};

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

      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());

    return proxyClass.isInstance(arg)
        // Equal proxy instances should mostly be instance of proxyClass
        // Under some edge cases (such as the proxy of JDK types serialized and then deserialized)
        // the proxy type may not be the same.
        // We first check isProxyClass() so that the common case of comparing with non-proxy objects
        // is efficient.

     * <p>
     * Note: This method no longer uses internal JDK APIs for safety and compatibility.
     * It now uses the standard String constructor.
     * </p>
     *
     * @param chars
     *            the char array
     * @return a new String, or null if the input is null
     * @deprecated This method originally used internal JDK APIs (sun.misc.SharedSecrets) for

    return new SingletonImmutableSet<>(e1);
  }

  /*
   * TODO: b/315526394 - Skip the Builder entirely for the of(...) methods, since we don't need to
   * worry that we might trigger the fallback to the JDK-backed implementation? (The varargs one
   * _could_, so we could keep it as it is. Or we could convince ourselves that hash flooding is
   * unlikely in practice there, too.)
   */

  /**

      <artifactId>maven-resolver-transport-file</artifactId>
    </dependency>
    <dependency>
      <groupId>org.apache.maven.resolver</groupId>
      <artifactId>maven-resolver-transport-jdk</artifactId>
    </dependency>

    <dependency>
      <groupId>org.codehaus.plexus</groupId>
      <artifactId>plexus-classworlds</artifactId>
    </dependency>
    <dependency>

   *     IOException}.
   */
  /*
   * The proper capitalization would be "swallowIoException." However:
   *
   * - It might be preferable to be consistent with the JDK precedent (which they stuck with even
   *   for "UncheckedIOException").
   *
   * - If we change the name, some of our callers break because our Android Lint ParameterName check

    // 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.
   */