is_offer: Union[bool, None] = None


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):
    return {"item_name": item.name, "item_id": item_id}
```

    * As connecting to an email server and sending an email tends to be "slow" (several seconds), you can return the response right away and send the email notification in the background.
* Processing data:
    * For example, let's say you receive a file that must go through a slow process, you can return a response of "Accepted" (HTTP 202) and process the file in the background.

## Using `BackgroundTasks` { #using-backgroundtasks }

   * Returns the iteration ordering of elements, given the order in which they were added to the
   * container. This method may return the original list unchanged, the original list modified in
   * place, or a different list.
   *
   * <p>If the order is non-deterministic, as with {@link java.util.HashSet}, this method can return
   * its input unmodified. Provided that the test suite is built without {@link

    taskDone = false;
    Callable<Boolean> task =
        new Callable<Boolean>() {
          @Override
          public Boolean call() {
            taskDone = true;
            return taskDone;
          }
        };
    List<Future<Boolean>> futureList = executor.invokeAll(ImmutableList.of(task), 10, MILLISECONDS);
    Future<Boolean> future = futureList.get(0);
    assertFalse(taskDone);

      bb.putLong(x);
    }
    return HashCode.fromBytes(bb.array());
  }

  public void testParanoid() {
    HashFn hf =
        new HashFn() {
          @Override
          public byte[] hash(byte[] input, int seed) {
            Hasher hasher = murmur3_128(seed).newHasher();
            Funnels.byteArrayFunnel().funnel(input, hasher);
            return hasher.hash().asBytes();
          }
        };

      new Function<@Nullable String, @Nullable Character>() {
        @Override
        public @Nullable Character apply(@Nullable String input) {
          return input == null ? null : input.charAt(0);
        }
      };

  @Override
  protected Table<String, Integer, Character> create(@Nullable Object... data) {
    Table<String, Integer, String> table = HashBasedTable.create();

    taskDone = false;
    Callable<Boolean> task =
        new Callable<Boolean>() {
          @Override
          public Boolean call() {
            taskDone = true;
            return taskDone;
          }
        };
    List<Future<Boolean>> futureList = executor.invokeAll(ImmutableList.of(task), 10, MILLISECONDS);
    Future<Boolean> future = futureList.get(0);
    assertFalse(taskDone);

   * collection in setUp(), but that caused problems when a tester changed the
   * value of list or collection but not both.
   */
  protected final List<E> getList() {
    return (List<E>) collection;
  }

  /**
   * {@inheritDoc}
   *
   * <p>The {@code AbstractListTester} implementation overrides {@link

   * Retrieves an instance of the appropriate type. The returned object may or may not be a new
   * instance, depending on the implementation.
   *
   * @return an instance of the appropriate type
   */
  @Override
  @ParametricNullness
  T get();

  /**
   * <i>May</i> return {@code true} if {@code object} is a {@code Supplier} that behaves identically
   * to this supplier.
   *

     * support filtering by all attributes (e.g. even though ATTR_DIRECTORY was
     * specified the server may still return objects that are not directories).
     */
    @Override
    public boolean accept(final SmbFile file) throws SmbException {
        return (file.getAttributes() & attributes) != 0;
    }