return this;
        } else if (tableEntry.equals(e)) { // not a new element, ignore
          return this;
        }
      }
      // we fell out of the loop due to a long run; fall back to JDK impl
      return new JdkBackedSetBuilderImpl<E>(this).add(e);
    }

    @Override
    SetBuilderImpl<E> copy() {
      return new RegularSetBuilderImpl<>(this);

        checkNotNull(cell.getValue(), "value");
        @SuppressWarnings("unchecked") // all supported methods are covariant
        Cell<R, C, V> immutableCell = (Cell<R, C, V>) cell;
        cells.add(immutableCell);
      } else {
        put(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
      }
      return this;
    }

    /**

    boolean collide = false; // True if last slot nonempty
    for (; ; ) {
      Cell[] as;
      Cell a;
      int n;
      long v;
      if ((as = cells) != null && (n = as.length) > 0) {
        if ((a = as[(n - 1) & h]) == null) {
          if (busy == 0) { // Try to attach new Cell
            Cell r = new Cell(x); // Optimistically create
            if (busy == 0 && casBusy()) {

    boolean collide = false; // True if last slot nonempty
    for (; ; ) {
      Cell[] as;
      Cell a;
      int n;
      long v;
      if ((as = cells) != null && (n = as.length) > 0) {
        if ((a = as[(n - 1) & h]) == null) {
          if (busy == 0) { // Try to attach new Cell
            Cell r = new Cell(x); // Optimistically create
            if (busy == 0 && casBusy()) {

        checkNotNull(cell.getValue(), "value");
        @SuppressWarnings("unchecked") // all supported methods are covariant
        Cell<R, C, V> immutableCell = (Cell<R, C, V>) cell;
        cells.add(immutableCell);
      } else {
        put(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
      }
      return this;
    }

    /**

    }

    Function<Cell<R, C, V1>, Cell<R, C, V2>> cellFunction() {
      return new Function<Cell<R, C, V1>, Cell<R, C, V2>>() {
        @Override
        public Cell<R, C, V2> apply(Cell<R, C, V1> cell) {
          return immutableCell(
              cell.getRowKey(), cell.getColumnKey(), function.apply(cell.getValue()));
        }
      };
    }

    @Override

   * row, and so on.
   *
   * <p>Each cell is an immutable snapshot of a row key / column key / value mapping, taken at the
   * time the cell is returned by a method call to the set or its iterator.
   */
  @Override
  public Set<Cell<R, C, V>> cellSet() {
    return super.cellSet();
  }

  @Override
  Iterator<Cell<R, C, V>> cellIterator() {
    return new CellIterator();
  }

    }

    @Override
    public Set<Cell<String, Integer, Character>> create(Object... elements) {
      Table<String, Integer, Character> table = createTable();
      for (Object element : elements) {
        @SuppressWarnings("unchecked")
        Cell<String, Integer, Character> cell = (Cell<String, Integer, Character>) element;
        table.put(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
      }

            });
    try {
      Cell<String, String, @Nullable Integer> cell = immutableCell("one", "uno", null);
      Stream.of((Cell<String, String, Integer>) cell).collect(collector);
      fail("Expected NullPointerException");
    } catch (NullPointerException expected) {
    }
  }

  public void testToTableConflict() {

    boolean collide = false; // True if last slot nonempty
    for (; ; ) {
      Cell[] as;
      Cell a;
      int n;
      long v;
      if ((as = cells) != null && (n = as.length) > 0) {
        if ((a = as[(n - 1) & h]) == null) {
          if (busy == 0) { // Try to attach new Cell
            Cell r = new Cell(x); // Optimistically create
            if (busy == 0 && casBusy()) {