@GwtIncompatible // serialization
  Object writeReplace() {
    Map<C, Integer> columnKeyToIndex = Maps.indexMap(columnKeySet());
    int[] cellColumnIndices = new int[cellSet().size()];
    int i = 0;
    for (Cell<R, C, V> cell : cellSet()) {
      // requireNonNull is safe because the cell exists in the table.
      cellColumnIndices[i++] = requireNonNull(columnKeyToIndex.get(cell.getColumnKey()));
    }

  @GwtIncompatible // serialization
  Object writeReplace() {
    Map<C, Integer> columnKeyToIndex = Maps.indexMap(columnKeySet());
    int[] cellColumnIndices = new int[cellSet().size()];
    int i = 0;
    for (Cell<R, C, V> cell : cellSet()) {
      // requireNonNull is safe because the cell exists in the table.
      cellColumnIndices[i++] = requireNonNull(columnKeyToIndex.get(cell.getColumnKey()));
    }

    }
  }

  public final void testConsistentHashCode() {
    for (ImmutableTable<Character, Integer, String> testInstance : getTestInstances()) {
      assertEquals(testInstance.cellSet().hashCode(), testInstance.hashCode());
    }
  }

   * cell views, as returned by {@link #cellSet}, are equal.
   */
  @Override
  boolean equals(@CheckForNull Object obj);

  /**
   * Returns the hash code for this table. The hash code of a table is defined as the hash code of
   * its cell view, as returned by {@link #cellSet}.
   */
  @Override
  int hashCode();

  // Mutators

    assertNull(INSTANCE.get('a', 1));
  }

  public void testIsEmpty() {
    assertTrue(INSTANCE.isEmpty());
  }

  public void testCellSet() {
    assertEquals(ImmutableSet.of(), INSTANCE.cellSet());
  }

  public void testColumn() {
    assertEquals(ImmutableMap.of(), INSTANCE.column(1));
  }

  public void testColumnKeySet() {
    assertEquals(ImmutableSet.of(), INSTANCE.columnKeySet());
  }

  public void testHashCode() {
    assertEquals(Objects.hashCode('a', 1, "blah"), testTable.hashCode());
  }

  public void testCellSet() {
    assertEquals(ImmutableSet.of(immutableCell('a', 1, "blah")), testTable.cellSet());
  }

  public void testColumn() {
    assertEquals(ImmutableMap.of(), testTable.column(0));
    assertEquals(ImmutableMap.of('a', "blah"), testTable.column(1));
  }

  public void testColumnKeySet() {

  }

  public void testCellSet() {
    for (ImmutableTable<Character, Integer, String> testInstance : getTestInstances()) {
      assertEquals(CELLS, testInstance.cellSet());
    }
  }

  public void testValues() {
    for (ImmutableTable<Character, Integer, String> testInstance : getTestInstances()) {
      assertThat(testInstance.values()).containsExactly("foo", "bar", "baz").inOrder();

  }

  public void testHashing() throws Exception {
    for (String stringToTest : INPUTS) {
      for (Table.Cell<String, SecretKey, HashFunction> cell : ALGORITHMS.cellSet()) {
        String algorithm = cell.getRowKey();
        SecretKey key = cell.getColumnKey();
        HashFunction hashFunc = cell.getValue();

  }

  public void testCellSetToString_ordered() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertEquals("[(bar,1)=b, (foo,1)=a, (foo,3)=c]", table.cellSet().toString());
  }

  public void testRowKeySetToString_ordered() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertEquals("[bar, foo]", table.rowKeySet().toString());
  }

   *
   * @return set of table cells consisting of row key / column key / value triplets
   */
  @Override
  public Set<Cell<R, C, @Nullable V>> cellSet() {
    return super.cellSet();
  }

  @Override
  Iterator<Cell<R, C, @Nullable V>> cellIterator() {
    return new AbstractIndexedListIterator<Cell<R, C, @Nullable V>>(size()) {
      @Override