}

  /**
   * {@inheritDoc}
   *
   * @throws NullPointerException if {@code columnKey} is {@code null}
   */
  @Override
  public ImmutableMap<R, V> column(C columnKey) {
    checkNotNull(columnKey, "columnKey");
    return MoreObjects.firstNonNull(
        (ImmutableMap<R, V>) columnMap().get(columnKey), ImmutableMap.of());
  }

  @Override
  public ImmutableSet<C> columnKeySet() {

  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

    }

    @Override
    public boolean contains(Object rowKey, Object columnKey) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.contains(rowKey, columnKey);
    }

    @Override
    public boolean containsColumn(Object columnKey) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.containsColumn(columnKey);
    }

    @Override
    public boolean containsRow(Object rowKey) {

  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() {

   *
   * @param rowKey key of row to search for
   * @param columnKey key of column to search for
   */
  boolean contains(
      @CompatibleWith("R") @Nullable Object rowKey,
      @CompatibleWith("C") @Nullable Object columnKey);

  /**
   * Returns {@code true} if the table contains a mapping with the specified row key.
   *

      Map<C, V> thisRow = requireNonNull(rows.get(rowKey));
      cellColumnInRowIndices[i] = thisRow.size();
      V oldValue = thisRow.put(columnKey, value);
      checkNoDuplicate(rowKey, columnKey, oldValue, value);
      requireNonNull(columns.get(columnKey)).put(rowKey, value);
    }
    this.cellRowIndices = cellRowIndices;
    this.cellColumnInRowIndices = cellColumnInRowIndices;

    }

    public ColumnInfo columnKey() {
        return _columnKey;
    }

    public ColumnInfo columnValue() {
        return _columnValue;
    }

    protected List<ColumnInfo> ccil() {
        List<ColumnInfo> ls = newArrayList();
        ls.add(columnCrawlingInfoId());
        ls.add(columnCreatedTime());
        ls.add(columnKey());
        ls.add(columnValue());
        return ls;

    }

    @Override
    public boolean contains(Object rowKey, Object columnKey) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.contains(rowKey, columnKey);
    }

    @Override
    public boolean containsColumn(Object columnKey) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.containsColumn(columnKey);
    }

    @Override
    public boolean containsRow(Object rowKey) {

   *
   * @param rowKey key of row to search for
   * @param columnKey key of column to search for
   */
  boolean contains(
      @CompatibleWith("R") @Nullable Object rowKey,
      @CompatibleWith("C") @Nullable Object columnKey);

  /**
   * Returns {@code true} if the table contains a mapping with the specified row key.
   *

      return (Table<R, C, V>) super.delegate();
    }

    @Override
    public boolean contains(@Nullable Object rowKey, @Nullable Object columnKey) {
      synchronized (mutex) {
        return delegate().contains(rowKey, columnKey);
      }
    }

    @Override
    public boolean containsRow(@Nullable Object rowKey) {
      synchronized (mutex) {