@SuppressWarnings("Immutable") // We don't modify this after construction.
  private final int[] cellRowIndices;

  // For each cell in iteration order, the index of that cell's column key in the list of column
  // keys present in that row.
  @SuppressWarnings("Immutable") // We don't modify this after construction.
  private final int[] cellColumnInRowIndices;

  SparseImmutableTable(

    //                                                                    ================
    // -----------------------------------------------------
    //                                       Column Property
    //                                       ---------------
    protected final Map<String, PropertyGateway> _epgMap = newHashMap();
    {
        setupEpg(_epgMap, et -> ((CrawlingInfoParam) et).getCrawlingInfoId(),

    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() {
    assertEquals(ImmutableSet.of(1), testTable.columnKeySet());
  }

  public void testColumnMap() {

    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);
    return containsColumn(columnKey)
        ? ImmutableMap.of(singleRowKey, singleValue)
        : ImmutableMap.<R, V>of();
  }

  @Override

    //                                                                    ================
    // -----------------------------------------------------
    //                                       Column Property
    //                                       ---------------
    protected final Map<String, PropertyGateway> _epgMap = newHashMap();
    {

    //                                                                    ================
    // -----------------------------------------------------
    //                                       Column Property
    //                                       ---------------
    protected final Map<String, PropertyGateway> _epgMap = newHashMap();
    {

    #  Does it check differences of column-def order?
    #  (except added or deleted columns)
    #
    #; isCheckColumnDefOrderDiff = false
    # - - - - - - - - - -/

    # /- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    # o isCheckDbCommentDiff: (NotRequired - Default false)
    #  Does it check differences of table or column or others comment?
    #
    #; isCheckDbCommentDiff = false

    //                                                                    ================
    // -----------------------------------------------------
    //                                       Column Property
    //                                       ---------------
    protected final Map<String, PropertyGateway> _epgMap = newHashMap();
    {

    public Set<Cell<R, C, V>> cellSet() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.cellSet();
    }

    @Override
    public Map<R, V> column(C columnKey) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.column(columnKey);
    }

    @Override
    public Set<C> columnKeySet() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.columnKeySet();
    }

    //                                                                    ================
    // -----------------------------------------------------
    //                                       Column Property
    //                                       ---------------
    protected final Map<String, PropertyGateway> _epgMap = newHashMap();
    {