private static final SparseImmutableTable<Character, Integer, String> SPARSE =
      new SparseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  private static final DenseImmutableTable<Character, Integer, String> DENSE =
      new DenseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  @Override
  Iterable<ImmutableTable<Character, Integer, String>> getTestInstances() {

  /**
   * Adds the given value.
   *
   * @param x the value to add
   */
  @Override
  public void add(long x) {
    Cell[] as;
    long b, v;
    int[] hc;
    Cell a;
    int n;
    if ((as = cells) != null || !casBase(b = base, b + x)) {
      boolean uncontended = true;
      if ((hc = threadHashCode.get()) == null
          || as == null
          || (n = as.length) < 1
          || (a = as[(n - 1) & hc[0]]) == null

  /**
   * Adds the given value.
   *
   * @param x the value to add
   */
  @Override
  public void add(long x) {
    Cell[] as;
    long b, v;
    int[] hc;
    Cell a;
    int n;
    if ((as = cells) != null || !casBase(b = base, b + x)) {
      boolean uncontended = true;
      if ((hc = threadHashCode.get()) == null
          || as == null
          || (n = as.length) < 1
          || (a = as[(n - 1) & hc[0]]) == null

 *   }
 * }
 *
 * public void testMySubtypes() throws Exception {
 *   new MySubtypeTests().testAllDeclarations();
 * }
 * }</pre>
 *
 * The calls to {@link #isSubtype} and {@link #notSubtype} tells the framework what assertions need
 * to be made.
 *
 * <p>The declaration methods must be public.
 */
@AndroidIncompatible // only used by android incompatible tests.
abstract class SubtypeTester implements Cloneable {

  private static final SparseImmutableTable<Character, Integer, String> SPARSE =
      new SparseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  private static final DenseImmutableTable<Character, Integer, String> DENSE =
      new DenseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  @Override
  Iterable<ImmutableTable<Character, Integer, String>> getTestInstances() {

          };
      Collections.sort(cells, comparator);
    }
    return forCellsInternal(cells, rowComparator, columnComparator);
  }

  static <R, C, V> RegularImmutableTable<R, C, V> forCells(Iterable<Cell<R, C, V>> cells) {
    return forCellsInternal(cells, null, null);
  }

  private static <R, C, V> RegularImmutableTable<R, C, V> forCellsInternal(

  /**
   * Adds the given value.
   *
   * @param x the value to add
   */
  @Override
  public void add(long x) {
    Cell[] as;
    long b, v;
    int[] hc;
    Cell a;
    int n;
    if ((as = cells) != null || !casBase(b = base, b + x)) {
      boolean uncontended = true;
      if ((hc = threadHashCode.get()) == null
          || as == null
          || (n = as.length) < 1
          || (a = as[(n - 1) & hc[0]]) == null

 *   }
 * }
 *
 * public void testMySubtypes() throws Exception {
 *   new MySubtypeTests().testAllDeclarations();
 * }
 * }</pre>
 *
 * The calls to {@link #isSubtype} and {@link #notSubtype} tells the framework what assertions need
 * to be made.
 *
 * <p>The declaration methods must be public.
 */
@AndroidIncompatible // only used by android incompatible tests.
abstract class SubtypeTester implements Cloneable {

      C columnKey = cell.getColumnKey();
      V value = cell.getValue();

      /*
       * These requireNonNull calls are safe because we construct the maps to hold all the provided
       * cells.
       */
      cellRowIndices[i] = requireNonNull(rowIndex.get(rowKey));
      Map<C, V> thisRow = requireNonNull(rows.get(rowKey));
      cellColumnInRowIndices[i] = thisRow.size();