/** Java Virtual Machine implementation name. */
  JAVA_VM_NAME("java.vm.name"),

  /** Java Runtime Environment specification version. */
  JAVA_SPECIFICATION_VERSION("java.specification.version"),

  /** Java Runtime Environment specification vendor. */
  JAVA_SPECIFICATION_VENDOR("java.specification.vendor"),

  /** Java Runtime Environment specification name. */
  JAVA_SPECIFICATION_NAME("java.specification.name"),

  /** Java Virtual Machine implementation name. */
  JAVA_VM_NAME("java.vm.name"),

  /** Java Runtime Environment specification version. */
  JAVA_SPECIFICATION_VERSION("java.specification.version"),

  /** Java Runtime Environment specification vendor. */
  JAVA_SPECIFICATION_VENDOR("java.specification.vendor"),

  /** Java Runtime Environment specification name. */
  JAVA_SPECIFICATION_NAME("java.specification.name"),

    // If the class is accessible to the system ClassLoader (ClassLoader.getSystemClassLoader())
    // then FRQ does not bother to load Finalizer.class through a separate ClassLoader. That happens
    // in our test environment, which foils the purpose of this test, so we disable the logic for
    // our test by setting a static field. We are changing the field in the parallel version of FRQ

    if (System.getProperty("com.google.appengine.runtime.environment") == null) {
      return false;
    }
    try {
      Class.forName("com.google.appengine.api.utils.SystemProperty");
    } catch (ClassNotFoundException e) {
      return false;
    }
    try {
      // If the current environment is null, we're not inside AppEngine.

    getChecked(immediateFuture("foo"), shadowClass);
    return new WeakReference<>(shadowLoader);
  }

  /*
   * TODO(cpovirk): It would be great to run all these tests (including class unloading) in an
   * environment that forces Futures.getChecked to its fallback WeakSetValidator. One awful way of
   * doing so would be to derive a separate test library by using remove_from_jar to strip out
   * ClassValueValidator.
   *

  }

  /*
   * Under Android, MyError propagates up and fails the test?
   *
   * TODO(b/218700094): Does this matter to prod users, or is it just a feature of our testing
   * environment? If the latter, maybe write a custom Executor that avoids failing the test when it
   * sees an Error?
   */
  @AndroidIncompatible
  public void testTaskThrowsError() throws Exception {

    // See Dispatcher.LegacyAsyncDispatcher for an explanation of why there aren't really any
    // useful testable guarantees about the behavior of that dispatcher in a multithreaded
    // environment. Here we simply test that all the expected dispatches happened in some order.
    assertThat(dispatchedSubscribers).containsExactly(i1, i2, i3, s1, s1, s1, s1, s2, s2, s2, s2);
  }

  public void testImmediateDispatcher() {

 * string formatting itself should not be a concern.
 *
 * <p>As with any performance concerns, you should consider profiling your code (in a production
 * environment if possible) before spending a lot of effort on tweaking a particular element.
 *
 * <h3>Other types of preconditions</h3>
 *
 * <p>Not every type of precondition failure is supported by these methods. Continue to throw

    // See Dispatcher.LegacyAsyncDispatcher for an explanation of why there aren't really any
    // useful testable guarantees about the behavior of that dispatcher in a multithreaded
    // environment. Here we simply test that all the expected dispatches happened in some order.
    assertThat(dispatchedSubscribers).containsExactly(i1, i2, i3, s1, s1, s1, s1, s2, s2, s2, s2);
  }

  public void testImmediateDispatcher() {

    // If the class is accessible to the system ClassLoader (ClassLoader.getSystemClassLoader())
    // then FRQ does not bother to load Finalizer.class through a separate ClassLoader. That happens
    // in our test environment, which foils the purpose of this test, so we disable the logic for
    // our test by setting a static field. We are changing the field in the parallel version of FRQ