// True if getValue never returns null.
    private boolean isFull() {
      return size == keyToIndex().size();
    }

    K getKey(int index) {
      return keyToIndex().keySet().asList().get(index);
    }

    @CheckForNull
    abstract V getValue(int keyIndex);

    @Override
    ImmutableSet<K> createKeySet() {
      return isFull() ? keyToIndex().keySet() : super.createKeySet();
    }

    // True if getValue never returns null.
    private boolean isFull() {
      return size == keyToIndex().size();
    }

    K getKey(int index) {
      return keyToIndex().keySet().asList().get(index);
    }

    @CheckForNull
    abstract V getValue(int keyIndex);

    @Override
    ImmutableSet<K> createKeySet() {
      return isFull() ? keyToIndex().keySet() : super.createKeySet();
    }

      Throwable throwable, Class<? extends Throwable> clazz, Object[] params) {
    assertThat(throwable).isInstanceOf(clazz);
    if (params.length == 1) {
      assertThat(throwable).hasMessageThat().isNull();
    } else if (params.length == 2) {
      assertThat(throwable).hasMessageThat().isEmpty();
    } else {
      assertThat(throwable)
          .hasMessageThat()

  }

  public void testImmediateVoidFuture() throws Exception {
    ListenableFuture<@Nullable Void> voidFuture = immediateVoidFuture();

    assertThat(getDone(voidFuture)).isNull();
    assertThat(getDoneFromTimeoutOverload(voidFuture)).isNull();
    assertThat(voidFuture.toString()).contains("[status=SUCCESS, result=[null]]");
  }

  public void testImmediateFailedFuture() throws Exception {

    ListenableFuture<?> statusFuture = closingFuture.statusFuture();
    waiter.awaitStarted();
    assertThat(statusFuture.isDone()).isFalse();
    waiter.awaitReturned();
    assertThat(getUninterruptibly(statusFuture)).isNull();
  }

  public void testStatusFuture_failure() throws Exception {
    ClosingFuture<String> closingFuture =
        ClosingFuture.submit(
            waiter.waitFor(

    assertThat(graph.edgeValue(2, 1).orElse(DEFAULT)).isEqualTo(DEFAULT);
    assertThat(graph.edgeValueOrDefault(1, 2, null)).isNull();
    assertThat(graph.edgeValueOrDefault(2, 1, null)).isNull();
    assertThat(graph.edgeValue(1, 2).orElse(null)).isNull();
    assertThat(graph.edgeValue(2, 1).orElse(null)).isNull();

    graph.putEdgeValue(1, 2, "valueA");
    graph.putEdgeValue(2, 1, "valueB");

  }

  /*
   * Tests for Predicates.isNull()
   */

  public void testIsNull_apply() {
    Predicate<@Nullable Integer> isNull = Predicates.isNull();
    assertTrue(isNull.apply(null));
    assertFalse(isNull.apply(1));
  }

  public void testIsNull_equality() {
    new EqualsTester()
        .addEqualityGroup(Predicates.isNull(), Predicates.isNull())
        .addEqualityGroup(Predicates.notNull())

    assertFalse(equalTo1.apply(null));
    Predicate<@Nullable Object> isNull = Equivalence.equals().equivalentTo(null);
    assertFalse(isNull.apply("1"));
    assertFalse(isNull.apply("2"));
    assertTrue(isNull.apply(null));

    new EqualsTester()
        .addEqualityGroup(equalTo1, Equivalence.equals().equivalentTo("1"))
        .addEqualityGroup(isNull)
        .addEqualityGroup(Equivalence.identity().equivalentTo("1"))

    return suite;
  }

  public void testAllocArraysDefault() {
    CompactHashSet<Integer> set = CompactHashSet.create();
    assertThat(set.needsAllocArrays()).isTrue();
    assertThat(set.elements).isNull();

    set.add(1);
    assertThat(set.needsAllocArrays()).isFalse();
    assertThat(set.elements).hasLength(CompactHashing.DEFAULT_SIZE);
  }

  public void testAllocArraysExpectedSize() {

    return suite;
  }

  public void testAllocArraysDefault() {
    CompactHashSet<Integer> set = CompactHashSet.create();
    assertThat(set.needsAllocArrays()).isTrue();
    assertThat(set.elements).isNull();

    set.add(1);
    assertThat(set.needsAllocArrays()).isFalse();
    assertThat(set.elements).hasLength(CompactHashing.DEFAULT_SIZE);
  }

  public void testAllocArraysExpectedSize() {