throws ExecutionException, InterruptedException {

    final ConcurrentHashMultiset<String> multiset = new ConcurrentHashMultiset<>(map);
    int nThreads = 20;
    int tasksPerThread = 10;
    int nTasks = nThreads * tasksPerThread;
    ExecutorService pool = Executors.newFixedThreadPool(nThreads);
    ImmutableList<String> keys = ImmutableList.of("a", "b", "c");
    try {
      List<Future<int[]>> futures = newArrayListWithExpectedSize(nTasks);

 * {@link Map} specified in the {@link Table} interface.
 *
 * <p>Note that this implementation is not synchronized. If multiple threads access this table
 * concurrently and one of the threads modifies the table, it must be synchronized externally.
 *
 * <p>See the Guava User Guide article on <a href=

 * methods for more details.
 *
 * <p>Note that this implementation is not synchronized. If multiple threads access the same cell of
 * an {@code ArrayTable} concurrently and one of the threads modifies its value, there is no
 * guarantee that the new value will be fully visible to the other threads. To guarantee that
 * modifications are visible, synchronize access to the table. Unlike other {@code Table}

    return (existingCounter == null) ? 0 : existingCounter.get();
  }

  /**
   * {@inheritDoc}
   *
   * <p>If the data in the multiset is modified by any other threads during this method, it is
   * undefined which (if any) of these modifications will be reflected in the result.
   */
  @Override
  public int size() {
    long sum = 0L;

      Integer uid = uids.get(obj);
      if (uid == null) {
        // One or more integer values could be skipped in the event of a race
        // to generate a UID for the same object from multiple threads, but
        // that shouldn't be a problem.
        uid = counter.getAndIncrement();
        Integer alreadySet = uids.putIfAbsent(obj, uid);
        if (alreadySet != null) {
          uid = alreadySet;
        }

      Integer uid = uids.get(obj);
      if (uid == null) {
        // One or more integer values could be skipped in the event of a race
        // to generate a UID for the same object from multiple threads, but
        // that shouldn't be a problem.
        uid = counter.getAndIncrement();
        Integer alreadySet = uids.putIfAbsent(obj, uid);
        if (alreadySet != null) {
          uid = alreadySet;
        }

* Add docs for correctly [using FastAPI with Peewee ORM](https://fastapi.tiangolo.com/advanced/sql-databases-peewee/). Including how to overwrite parts of Peewee to correctly handle async threads. PR [#789](https://github.com/tiangolo/fastapi/pull/789).

## 0.45.0

* Add support for OpenAPI Callbacks:
    * New docs: [OpenAPI Callbacks](https://fastapi.tiangolo.com/advanced/openapi-callbacks/).