private static final SparseImmutableTable<Character, Integer, String> SPARSE =
      new SparseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  private static final DenseImmutableTable<Character, Integer, String> DENSE =
      new DenseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  @Override
  Iterable<ImmutableTable<Character, Integer, String>> getTestInstances() {

  private static final SparseImmutableTable<Character, Integer, String> SPARSE =
      new SparseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  private static final DenseImmutableTable<Character, Integer, String> DENSE =
      new DenseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  @Override
  Iterable<ImmutableTable<Character, Integer, String>> getTestInstances() {

    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();

    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();