- tutorial/handling-errors.md
    - tutorial/path-operation-configuration.md
    - tutorial/encoder.md
    - tutorial/body-updates.md
    - Dependencies:
      - tutorial/dependencies/index.md
      - tutorial/dependencies/classes-as-dependencies.md
      - tutorial/dependencies/sub-dependencies.md
      - tutorial/dependencies/dependencies-in-path-operation-decorators.md
      - tutorial/dependencies/global-dependencies.md

app = FastAPI()


@app.get("/items/")
async def read_items():
    return [{"item_id": "Foo"}]


def use_route_names_as_operation_ids(app: FastAPI) -> None:
    """
    Simplify operation IDs so that generated API clients have simpler function
    names.

    Should be called only after all routes have been added.
    """
    for route in app.routes:
        if isinstance(route, APIRoute):

    return count(object) > 0;
  }

  /**
   * Guaranteed to throw an exception and leave the collection unmodified.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final int add(E element, int occurrences) {

  }

  // mutators (not supported)

  /**
   * Guaranteed to throw an exception and leave the multimap unmodified.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  // DoNotCall wants this to be final, but we want to override it to return more specific types.

     * Data transfer object representing operating system statistics.
     */
    public static class OsObj {
        /**
         * Default constructor.
         */
        public OsObj() {
            // Default constructor
        }

        /** Memory statistics for the operating system. */
        public OsMemoryObj memory;
        /** CPU statistics for the operating system. */
        public OsCpuObj cpu;

8. Notice that this *path operation function* uses regular `def` instead of `async def`.

    As always, in FastAPI you can combine `def` and `async def` as needed.

    If you need a refresher about when to use which, check out the section _"In a hurry?"_ in the docs about [`async` and `await`](../async.md#in-a-hurry){.internal-link target=_blank}.

    return this.<T>trustedPut(type.rejectTypeVariables(), value);
  }

  /**
   * Not supported. Use {@link #putInstance} instead.
   *
   * @deprecated unsupported operation
   * @throws UnsupportedOperationException always
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")

    """
    Create an invoice.

    This will (let's imagine) let the API user (some external developer) create an
    invoice.

    And this path operation will:

    * Send the invoice to the client.
    * Collect the money from the client.
    * Send a notification back to the API user (the external developer), as a callback.

    // DELETE /api/admin/storage/delete/{id}/
    /**
     * Deletes a file from storage.
     * @param id The ID of the file to delete.
     * @return A JSON response indicating the success or failure of the operation.
     */
    @Execute
    public JsonResponse<ApiResult> delete$delete(final String id) {
        final PathInfo pi = convertToItem(id);
        if (StringUtil.isEmpty(pi.getName())) {

     * @param flags
     *            Flags that control the behavior of the operation. When all
     *            name associated with SIDs will be required, the SID_FLAG_RESOLVE_SIDS
     *            flag should be used which causes all group member SIDs to be resolved
     *            together in a single more efficient operation.
     * @return a map of group SID to member SIDs