* elements directly and null for empty positions, we store indices of the keys in the hash table,
   * and ABSENT for empty positions.  We then look up the keys in alternatingKeysAndValues.
   *
   * (The index actually stored is the index of the key in alternatingKeysAndValues, which is
   * double the index of the entry in entrySet.asList.)
   *

                  }
                }
              }));
    }

    @VisibleForTesting
    void addShutdownHook(Thread hook) {
      Runtime.getRuntime().addShutdownHook(hook);
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // TODO
  private static void useDaemonThreadFactory(ThreadPoolExecutor executor) {
    executor.setThreadFactory(

  private TestSuppressor suppressor;

  @Override
  protected void setUp() throws Exception {
    suppressor = new TestSuppressor();
  }

  @AndroidIncompatible // TODO(cpovirk): Look up Build.VERSION.SDK_INT reflectively.
  public void testCreate() {
    assertThat(Closer.create().suppressor).isInstanceOf(Closer.SuppressingSuppressor.class);
  }

  public void testNoExceptionsThrown() throws IOException {

   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
  // @IgnoreJRERequirement is not necessary because this compiles down to a constant.
  // (which is fortunate because Animal Sniffer doesn't look for @IgnoreJRERequirement on fields)
  static final int SPLITERATOR_CHARACTERISTICS =
      Spliterator.IMMUTABLE | Spliterator.NONNULL | Spliterator.ORDERED;

  ImmutableCollection() {}

  private TestSuppressor suppressor;

  @Override
  protected void setUp() throws Exception {
    suppressor = new TestSuppressor();
  }

  @AndroidIncompatible // TODO(cpovirk): Look up Build.VERSION.SDK_INT reflectively.
  public void testCreate() {
    assertThat(Closer.create().suppressor).isInstanceOf(Closer.SuppressingSuppressor.class);
  }

  public void testNoExceptionsThrown() throws IOException {