assertThat(transpose(transpose)).isSameInstanceAs(directedGraph);
    AbstractGraphTest.validateGraph(transpose.asGraph());

    assertThat(transpose.edgeValueOrDefault(N1, N2, null)).isNull();
    for (Integer node : directedGraph.nodes()) {
      assertThat(directedGraph.inDegree(node)).isSameInstanceAs(transpose.outDegree(node));

      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()

    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())

    // 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();
    }

            return LIST_ITEM;
        }

        @Override
        public boolean isNull() {
            return (size() == 0);
        }

        void normalize() {
            for (int i = size() - 1; i >= 0; i--) {
                Item lastItem = get(i);

                if (lastItem.isNull()) {
                    if (i == size() - 1 || get(i + 1).getType() == STRING_ITEM) {

    } catch (NumberFormatException expected) {
    }
  }

  public void testStringConverter_nullConversions() {
    assertThat(Floats.stringConverter().convert(null)).isNull();
    assertThat(Floats.stringConverter().reverse().convert(null)).isNull();
  }

  @J2ktIncompatible
  @GwtIncompatible // Float.toString returns different value in GWT.
  public void testStringConverter_reverse() {

      if (from == State.STARTING) {
        try {
          service.awaitRunning();
          fail();
        } catch (IllegalStateException expected) {
          assertThat(expected).hasCauseThat().isNull();
          assertThat(expected)
              .hasMessageThat()
              .isEqualTo("Expected the service " + service + " to be RUNNING, but was STOPPING");
        }
      }

    } catch (NumberFormatException expected) {
    }
  }

  public void testStringConverter_nullConversions() {
    assertThat(Shorts.stringConverter().convert(null)).isNull();
    assertThat(Shorts.stringConverter().reverse().convert(null)).isNull();
  }

  public void testStringConverter_reverse() {
    Converter<String, Short> converter = Shorts.stringConverter();

    assertThat(Longs.tryParse("")).isNull();
    assertThat(Longs.tryParse("-")).isNull();
    assertThat(Longs.tryParse("+1")).isNull();
    assertThat(Longs.tryParse("999999999999999999999999")).isNull();
    assertWithMessage("Max long + 1")
        .that(Longs.tryParse(BigInteger.valueOf(MAX_VALUE).add(BigInteger.ONE).toString()))
        .isNull();
    assertWithMessage("Max long * 10")