private ArrayTable(Iterable<? extends R> rowKeys, Iterable<? extends C> columnKeys) {
    this.rowList = ImmutableList.copyOf(rowKeys);
    this.columnList = ImmutableList.copyOf(columnKeys);
    checkArgument(rowList.isEmpty() == columnList.isEmpty());

    /*
     * TODO(jlevy): Support only one of rowKey / columnKey being empty? If we
     * do, when columnKeys is empty but rowKeys isn't, rowKeyList() can contain

                    List<Integer> columnKeys = new ArrayList<>();
                    for (Object element : elements) {
                      @SuppressWarnings("unchecked")
                      Cell<String, Integer, Character> cell =
                          (Cell<String, Integer, Character>) element;
                      columnKeys.add(cell.getColumnKey());
                    }

  public boolean contains(@Nullable Object rowKey, @Nullable Object columnKey) {
    Map<C, V> row = safeGet(rowMap(), rowKey);
    return row != null && Maps.safeContainsKey(row, columnKey);
  }

  @Override
  public @Nullable V get(@Nullable Object rowKey, @Nullable Object columnKey) {
    Map<C, V> row = safeGet(rowMap(), rowKey);
    return (row == null) ? null : safeGet(row, columnKey);
  }

  @Override
  public boolean isEmpty() {

  public boolean contains(@Nullable Object rowKey, @Nullable Object columnKey) {
    Map<C, V> row = safeGet(rowMap(), rowKey);
    return row != null && Maps.safeContainsKey(row, columnKey);
  }

  @Override
  public @Nullable V get(@Nullable Object rowKey, @Nullable Object columnKey) {
    Map<C, V> row = safeGet(rowMap(), rowKey);
    return (row == null) ? null : safeGet(row, columnKey);
  }

  @Override
  public boolean isEmpty() {

  SingletonImmutableTable(R rowKey, C columnKey, V value) {
    this.singleRowKey = checkNotNull(rowKey);
    this.singleColumnKey = checkNotNull(columnKey);
    this.singleValue = checkNotNull(value);
  }

  SingletonImmutableTable(Cell<R, C, V> cell) {
    this(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
  }

  @Override
  public ImmutableMap<R, V> column(C columnKey) {
    checkNotNull(columnKey);

  @Override
  public Map<R, V> column(C columnKey) {
    return new Column(columnKey);
  }

  private final class Column extends ViewCachingAbstractMap<R, V> {
    final C columnKey;

    Column(C columnKey) {
      this.columnKey = checkNotNull(columnKey);
    }

    @Override
    public @Nullable V put(R key, V value) {
      return StandardTable.this.put(key, columnKey, value);
    }

    @Override