builder.put('b', 2, "foo");
    builder.put('b', 1, "bar");
    builder.put('a', 2, "baz");
    Table<Character, Integer, String> table = builder.build();
    assertThat(table).isInstanceOf(DenseImmutableTable.class);
    validateReserialization(table);
  }

  public void testDenseSerialization_rowOrder() {
    ImmutableTable.Builder<Character, Integer, String> builder = ImmutableTable.builder();

      expected.put(key, -i);
    }
    ImmutableMap<ClassWithTerribleHashCode, Integer> map = builder.buildKeepingLast();
    assertThat(map).containsExactlyEntriesIn(expected).inOrder();
    assertThat(map).isInstanceOf(JdkBackedImmutableMap.class);
  }

  @GwtIncompatible // Pattern, Matcher
  public void testBuilder_keepingLast_thenOrThrow() {
    ImmutableMap.Builder<String, Integer> builder =