checkNotNull(cell.getRowKey(), "row");
        checkNotNull(cell.getColumnKey(), "column");
        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());
      }

        checkNotNull(cell.getRowKey(), "row");
        checkNotNull(cell.getColumnKey(), "column");
        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());
      }

        h ^= h << 5;
        hc[0] = h; // Record index for next time
      } else if (busy == 0 && cells == as && casBusy()) {
        boolean init = false;
        try { // Initialize table
          if (cells == as) {
            Cell[] rs = new Cell[2];
            rs[h & 1] = new Cell(x);
            cells = rs;
            init = true;
          }
        } finally {
          busy = 0;
        }

      return Maps.transformValues(fromTable.column(columnKey), function);
    }

    Cell<R, C, V2> applyToValue(Cell<R, C, V1> cell) {
      return immutableCell(cell.getRowKey(), cell.getColumnKey(), function.apply(cell.getValue()));
    }

    @Override
    Iterator<Cell<R, C, V2>> cellIterator() {
      return Iterators.transform(fromTable.cellSet().iterator(), this::applyToValue);
    }

    /**
     * Compares the specified object with this cell for equality. Two cells are equal when they have
     * equal row keys, column keys, and values.
     */
    @Override
    boolean equals(@Nullable Object obj);

    /**
     * Returns the hash code of this cell.
     *
     * <p>The hash code of a table cell is equal to {@link Objects#hashCode}{@code (e.getRowKey(),
     * e.getColumnKey(), e.getValue())}.
     */

   * the second row key, and so on.
   *
   * <p>The value in the returned cells may change if the table subsequently changes.
   *
   * @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 (Table<String, String, Integer>) table;
            });
    Cell<String, String, @Nullable Integer> cell = immutableCell("one", "uno", null);
    assertThrows(
        NullPointerException.class,
        () -> Stream.of((Cell<String, String, Integer>) cell).collect(collector));
  }

  public void testToTableConflict() {
    Collector<Cell<String, String, Integer>, ?, Table<String, String, Integer>> collector =

    }

    @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());
      }

  }

  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();
        assertMacHashing(HashTestUtils.ascii(stringToTest), algorithm, key, hashFunc);
      }
    }
  }

      }
    }
  }

  public void testKnownUtf8Hashing() {
    for (Cell<HashFunction, String, String> cell : KNOWN_HASHES.cellSet()) {
      HashFunction func = cell.getRowKey();
      String input = cell.getColumnKey();
      String expected = cell.getValue();
      assertEquals(
          String.format(Locale.ROOT, "Known hash for hash(%s, UTF_8) failed", input),