*
   * <p>This is guaranteed to return zero if the dataset contains a single pair of finite values. It
   * is not guaranteed to return zero when the dataset consists of the same pair of values multiple
   * times, due to numerical errors.
   *
   * <h3>Non-finite values</h3>
   *
   * <p>If the dataset contains any non-finite values ({@link Double#POSITIVE_INFINITY}, {@link

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    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):

     */
    boolean contains(@Nonnull Version version);

    /**
     * Returns the upper boundary of this range, or {@code null} if none.
     */
    @Nullable
    Boundary getUpperBoundary();

    /**
     * Returns the lower boundary of this range, or {@code null} if none.
     */
    @Nullable
    Boundary getLowerBoundary();

    /**
     * {@return the string representation of this version}
     */

  }

  /*
   * TODO(jlevy): Consider creating a merge() method, similar to putAll() but
   * copying non-null values only.
   */

  /**
   * {@inheritDoc}
   *
   * <p>If {@code table} is an {@code ArrayTable}, its null values will be stored in this table,
   * possibly replacing values that were previously non-null.
   *
   * @throws NullPointerException if {@code table} has a null key

  /**
   * Returns the <a href="http://en.wikipedia.org/wiki/Arithmetic_mean">arithmetic mean</a> of the
   * values. The count must be non-zero.
   *
   * <p>If these values are a sample drawn from a population, this is also an unbiased estimator of
   * the arithmetic mean of the population.
   *
   * <h3>Non-finite values</h3>
   *
   * <p>If the dataset contains {@link Double#NaN} then the result is {@link Double#NaN}. If it

    * Вы можете задать его URL с помощью параметра `docs_url`.
    * Вы можете отключить это с помощью настройки `docs_url=None`.
* **ReDoc**: отображаемый по адресу `/redoc`.
    * Вы можете задать его URL с помощью параметра `redoc_url`.
    * Вы можете отключить это с помощью настройки `redoc_url=None`.

К примеру, чтобы задать отображение Swagger UI по адресу `/documentation` и отключить ReDoc:

## Parâmetros opcionais

Da mesma forma, você pode declarar parâmetros de consulta opcionais, definindo o valor padrão para `None`:

{* ../../docs_src/query_params/tutorial002_py310.py hl[7] *}

Nesse caso, o parâmetro da função `q` será opcional, e `None` será o padrão.

/// check | Verificar

public interface Location {

    /**
     * Return the line number where the current event ends,
     * returns -1 if none is available.
     * @return the current line number
     */
    int getLineNumber();

    /**
     * Return the column number where the current event ends,
     * returns -1 if none is available.
     * @return the current column number
     */
    int getColumnNumber();

    /**

      // will not be transmitted.
      val conditionName: String
      val conditionValue: String?
      when {
        etag != null -> {
          conditionName = "If-None-Match"
          conditionValue = etag
        }

        lastModified != null -> {
          conditionName = "If-Modified-Since"
          conditionValue = lastModifiedString
        }

Der erste Schritt besteht darin, die automatischen Dokumentationen zu deaktivieren, da diese standardmäßig das Standard-CDN verwenden.

Um diese zu deaktivieren, setzen Sie deren URLs beim Erstellen Ihrer `FastAPI`-App auf `None`:

{* ../../docs_src/custom_docs_ui/tutorial001.py hl[8] *}

### Die benutzerdefinierten Dokumentationen hinzufügen

Jetzt können Sie die *Pfadoperationen* für die benutzerdefinierten Dokumentationen erstellen.