Optional:    true,
			Type:        "string",
			Sensitive:   true,
			Secret:      true,
		},
		config.HelpKV{
			Key:         EnableHTTP2,
			Description: "Enable experimental HTTP2 support to connect to plugin service" + defaultHelpPostfix(EnableHTTP2),
			Optional:    true,
			Type:        "bool",
		},
		config.HelpKV{

			Optional:    true,
			Type:        "duration",
		},
		config.HelpKV{
			Key:         KeyRotationWorkersWait,
			Description: `maximum sleep duration between objects to slow down batch keyrotation operation` + defaultHelpPostfix(KeyRotationWorkersWait),
			Optional:    true,
			Type:        "duration",
		},
		config.HelpKV{

from typing import Optional

import pytest
from fastapi import FastAPI
from fastapi.exceptions import ResponseValidationError
from fastapi.testclient import TestClient
from pydantic.dataclasses import dataclass

app = FastAPI()


@dataclass
class Item:
    name: str
    price: Optional[float] = None
    owner_ids: Optional[list[int]] = None


@app.get("/items/invalid", response_model=Item)
def get_invalid():

from typing import Optional


def get_authorization_scheme_param(
    authorization_header_value: Optional[str],
) -> tuple[str, str]:
    if not authorization_header_value:
        return "", ""
    scheme, _, param = authorization_header_value.partition(" ")

     *
     * @return the optional POM file
     */
    @Nonnull
    Optional<Path> getPomFile();

    /**
     * Gets the project that was built.
     *
     * @return The project that was built or {@code null} if an error occurred and this result accompanies a
     *         {@link ProjectBuilderException}.
     */
    @Nonnull
    Optional<Project> getProject();

    /**

# Apache Maven Debug Script
#
# Environment Variable Prerequisites
#
#   JAVA_HOME           (Optional) Points to a Java installation.
#   MAVEN_OPTS          (Optional) Java runtime options used when Maven is executed.
#   MAVEN_SKIP_RC       (Optional) Flag to disable loading of mavenrc files.
#   MAVEN_DEBUG_ADDRESS (Optional) Set the debug address. Default value is localhost:8000

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009_py39.py!}
```

O uso de `Optional[str]` em vez de apenas `str` permitirá que o editor o ajude a detectar erros, onde você pode estar assumindo que um valor é sempre um `str`, quando na verdade também pode ser `None`.

        void shouldBeApplicableWhenModelOptionTrue() {
            UpgradeOptions options = mock(UpgradeOptions.class);
            when(options.model()).thenReturn(Optional.of(true));
            when(options.all()).thenReturn(Optional.empty());

            UpgradeContext context = createMockContext(options);

            assertTrue(strategy.isApplicable(context), "Strategy should be applicable when --model is true");

from typing import Optional

from fastapi import Depends, FastAPI, Security
from fastapi.security.open_id_connect_url import OpenIdConnect
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

oid = OpenIdConnect(openIdConnectUrl="/openid", auto_error=False)


class User(BaseModel):
    username: str


def get_current_user(oauth_header: Optional[str] = Security(oid)):
    if oauth_header is None:

comment  (sentence)  optionally add a comment to this setting
```

or environment variables

```
KEY:
site  label the server and its location

ARGS:
MINIO_SITE_NAME     (string)    name for the site e.g. "cal-rack0"
MINIO_SITE_REGION   (string)    name of the location of the server e.g. "us-west-1"
MINIO_SITE_COMMENT  (sentence)  optionally add a comment to this setting
```

Example: