/** Table of cells. When non-null, size is a power of 2. */
  @CheckForNull transient volatile Cell[] cells;

  /**
   * Base value, used mainly when there is no contention, but also as a fallback during table
   * initialization races. Updated via CAS.
   */
  transient volatile long base;

  /** Spinlock (locked via CAS) used when resizing and/or creating Cells. */
  transient volatile int busy;

  /** Table of cells. When non-null, size is a power of 2. */
  @CheckForNull transient volatile Cell[] cells;

  /**
   * Base value, used mainly when there is no contention, but also as a fallback during table
   * initialization races. Updated via CAS.
   */
  transient volatile long base;

  /** Spinlock (locked via CAS) used when resizing and/or creating Cells. */
  transient volatile int busy;

  /** Table of cells. When non-null, size is a power of 2. */
  @CheckForNull transient volatile Cell[] cells;

  /**
   * Base value, used mainly when there is no contention, but also as a fallback during table
   * initialization races. Updated via CAS.
   */
  transient volatile long base;

  /** Spinlock (locked via CAS) used when resizing and/or creating Cells. */
  transient volatile int busy;

     * @since 31.0
     */
    public ImmutableTable<R, C, V> buildOrThrow() {
      int size = cells.size();
      switch (size) {
        case 0:
          return of();
        case 1:
          return new SingletonImmutableTable<>(Iterables.getOnlyElement(cells));
        default:
          return RegularImmutableTable.forCells(cells, rowComparator, columnComparator);
      }
    }
  }

  ImmutableTable() {}

     * @since 31.0
     */
    public ImmutableTable<R, C, V> buildOrThrow() {
      int size = cells.size();
      switch (size) {
        case 0:
          return of();
        case 1:
          return new SingletonImmutableTable<>(Iterables.getOnlyElement(cells));
        default:
          return RegularImmutableTable.forCells(cells, rowComparator, columnComparator);
      }
    }
  }

  ImmutableTable() {}

public final class Tables {
  private Tables() {}

  /**
   * Returns a {@link Collector} that accumulates elements into a {@code Table} created using the
   * specified supplier, whose cells are generated by applying the provided mapping functions to the
   * input elements. Cells are inserted into the generated {@code Table} in encounter order.
   *
   * <p>If multiple input elements map to the same row and column, an {@code IllegalStateException}

   * update the underlying table, and vice versa. The cell set does not support the {@code add} or
   * {@code addAll} methods.
   *
   * @return set of table cells consisting of row key / column key / value triplets
   */
  Set<Cell<R, C, V>> cellSet();

  /**
   * Returns a set of row keys that have one or more values in the table. Changes to the set will

      return doGetRate();
    }
  }

  abstract double doGetRate();

  /**
   * Acquires a single permit from this {@code RateLimiter}, blocking until the request can be
   * granted. Tells the amount of time slept, if any.
   *
   * <p>This method is equivalent to {@code acquire(1)}.
   *
   * @return time spent sleeping to enforce rate, in seconds; 0.0 if not rate-limited

          }
        };

    recursiveCache = CacheBuilder.newBuilder().weakKeys().weakValues().build(recursiveLoader);
    cacheRef.set(recursiveCache);

    // tells the test when the computation has completed
    final CountDownLatch doneSignal = new CountDownLatch(1);

    Thread thread =
        new Thread() {
          @Override
          public void run() {

   *
   * <p>The returned set's iterator traverses the mappings with the first row key, the mappings with
   * 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