* simply be rethrown. The default implementation returns <code>null</code>.
     * @return the authentication credentials or null if none available
     */
    protected NtlmPasswordAuthenticator getNtlmPasswordAuthentication() {
        return null;
    }

   *
   * @throws IllegalArgumentException if the stream consists of two or more elements.
   * @throws NullPointerException if any element in the stream is {@code null}.
   * @return {@code Optional.of(onlyElement)} if the stream has exactly one element (must not be
   *     {@code null}) and returns {@code Optional.empty()} if it has none.
   */
  @SuppressWarnings("unchecked")

    * `dict`의 값(value)는 `float`타입이다. (각 아이템의 가격(price))

#### `Optional`

`str`과 같이 타입을 선언할 때 `Optional`을 쓸 수도 있는데, "선택적(Optional)"이기때문에 `None`도 될 수 있습니다:

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009.py!}
```

`Optional[str]`을 `str` 대신 쓰게 되면, 특정 값이 실제로는 `None`이 될 수도 있는데 항상 `str`이라고 가정하는 상황에서 에디터가 에러를 찾게 도와줄 수 있습니다.

#### Generic(제네릭) 타입

이 타입은 대괄호 안에 매개변수를 가지며, 종류는:

* `List`

	public static final field BODY Lokhttp3/logging/HttpLoggingInterceptor$Level;
	public static final field HEADERS Lokhttp3/logging/HttpLoggingInterceptor$Level;
	public static final field NONE Lokhttp3/logging/HttpLoggingInterceptor$Level;
	public static fun getEntries ()Lkotlin/enums/EnumEntries;
	public static fun valueOf (Ljava/lang/String;)Lokhttp3/logging/HttpLoggingInterceptor$Level;

そして呼び出すと:

```Python
print(user_dict)
```

以下のようなPythonの`dict`を得ることができます:

```Python
{
    'username': 'john',
    'password': 'secret',
    'email': '******@****.***',
    'full_name': None,
}
```

#### `dict`の展開

`user_dict`のような`dict`を受け取り、それを`**user_dict`を持つ関数（またはクラス）に渡すと、Pythonはそれを「展開」します。これは`user_dict`のキーと値を直接キー・バリューの引数として渡します。

そこで上述の`user_dict`の続きを以下のように書くと:

```Python

     */
    public boolean available() {
        final String ssoType = getSsoType();
        if (logger.isDebugEnabled()) {
            logger.debug("sso.type: {}", ssoType);
        }
        return !Constants.NONE.equals(ssoType);
    }

    /**
     * Attempts to obtain login credentials using the configured SSO authenticator.
     *
     * @return The login credential from SSO authentication, or null if SSO is not available

            determineSubProjectClassTimes(testCoverage, buildProjectClassTimes)?.toMutableMap()
                ?: return validSubprojects.map { SmallSubprojectBucket(it, ParallelizationMethod.None) }

        validSubprojects.forEach {
            if (!subProjectToClassTimes.containsKey(it.name)) {
                subProjectToClassTimes[it.name] = emptyList()
            }
        }

    ): FunctionalTest {
        val parallelizationMethod =
            when (testCoverage.os) {
                Os.LINUX -> ParallelizationMethod.TestDistribution
                else -> ParallelizationMethod.None
            }

        return FunctionalTest(
            model,
            testCoverage.getBucketUuid(model, bucketIndex),
            "${testCoverage.asName()} ($startInclusive <= gradle <$endExclusive)",

{* ../../docs_src/path_params_numeric_validations/tutorial001_py310.py hl[8] *}

/// note | Nota

Um parâmetro de rota é sempre obrigatório, como se fizesse parte da rota.

Então, você deve declará-lo com `...` para marcá-lo como obrigatório.

Mesmo que você declare-o como `None` ou defina um valor padrão, isso não teria efeito algum, o parâmetro ainda seria obrigatório.

///

Het tweede argument van <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> is de standaardwaarde die wordt geretourneerd.

Als je dit niet meegeeft, is de standaardwaarde `None`. In dit geval gebruiken we standaard `"World"`.

///

Dan zou je dat Python-programma kunnen aanroepen:

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console