* within the same test have no effect.
   */
  final void threadRecordFailure(Throwable t) {
    threadFailure.compareAndSet(null, t);
  }

  /**
   * Extra checks that get done for all test cases.
   *
   * <p>Triggers test case failure if any thread assertions have failed, by rethrowing, in the test
   * harness thread, any exception recorded earlier by threadRecordFailure.
   *

 * future.addListener(new Runnable() {
 *   public void run() {
 *     processedCount.incrementAndGet();
 *     inFlight.remove(name);
 *     lastProcessed.set(name);
 *     logger.info("Done with {0}", name);
 *   }
 * }, executor);
 * }
 *
 * <h3>How to get an instance</h3>
 *
 * <p>We encourage you to return {@code ListenableFuture} from your methods so that your users can

            dstIndex += ((AndXServerMessageBlock) andx).writeAndXWireFormat(dst, dstIndex);
        } else {
            // the andx smb is not of type andx so lets just write it here and
            // were done.
            final int andxStart = dstIndex;
            andx.wordCount = andx.writeParameterWordsWireFormat(dst, dstIndex);
            dstIndex += andx.wordCount + 1;
            andx.wordCount /= 2;

 *   <li>{@code override}: Completely replaces the element</li>
 *   <li>{@code remove}: Removes the element</li>
 * </ul>
 *
 * <p>For complex XML structures, combining can also be done based on:</p>
 * <ul>
 *   <li>ID: Using the {@code combine.id} attribute</li>
 *   <li>Keys: Using the {@code combine.keys} attribute with comma-separated key names</li>
 * </ul>
 *
 * @since 4.0.0
 */

///

## Optionaler Datei-Upload { #optional-file-upload }

Sie können eine Datei optional machen, indem Sie Standard-Typannotationen verwenden und den Defaultwert auf `None` setzen:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

## `UploadFile` mit zusätzlichen Metadaten { #uploadfile-with-additional-metadata }

你可以宣告與 `Query` 相同的所有參數。

例如，若要為路徑參數 `item_id` 宣告 `title` 中繼資料，可以這樣寫：

{* ../../docs_src/path_params_numeric_validations/tutorial001_an_py310.py hl[10] *}

/// note

路徑參數一定是必填，因為它必須是路徑的一部分。即使你將其宣告為 `None` 或設定預設值，也不會有任何影響，它仍然是必填。

///

## 依需求調整參數順序 { #order-the-parameters-as-you-need }

/// tip

如果你使用 `Annotated`，這點大概沒那麼重要或必要。

///

假設你想把查詢參數 `q` 宣告為必要的 `str`。

            "axisLabel": "",
            "axisPlacement": "auto",
            "barAlignment": 0,
            "drawStyle": "line",
            "fillOpacity": 10,
            "gradientMode": "none",
            "hideFrom": {
              "legend": false,
              "tooltip": false,
              "viz": false
            },
            "insertNulls": false,
            "lineInterpolation": "linear",

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None
    tags: set[str] = set()


@app.post("/items/", tags=["items"])
async def create_item(item: Item) -> Item:
    return item


@app.get("/items/", tags=["items"])
async def read_items():

from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


app = FastAPI()


@app.post("/items/")
async def create_item(item: Item):
    item_dict = item.model_dump()
    if item.tax is not None:
        price_with_tax = item.price + item.tax
        item_dict.update({"price_with_tax": price_with_tax})

   *
   *  - "Lax": the cookie is omitted when the subject URL is an embedded resource. It is sent for
   *    potentially-destructive navigation. This is the default value.
   *
   *  - "None": the cookie is always sent. The "Secure" attribute must also be set when setting this
   *    value.
   */
  @get:JvmName("sameSite")
  val sameSite: String?,
) {
  /**