"type": "integer",
                                    "maximum": 100,
                                    "exclusiveMinimum": 0,
                                    "default": 100,
                                    "title": "Limit",
                                },
                            },
                            {
                                "name": "offset",

app = FastAPI()


@app.get("/hidden_cookie")
async def hidden_cookie(
    hidden_cookie: Optional[str] = Cookie(default=None, include_in_schema=False),
):
    return {"hidden_cookie": hidden_cookie}


@app.get("/hidden_header")
async def hidden_header(
    hidden_header: Optional[str] = Header(default=None, include_in_schema=False),
):
    return {"hidden_header": hidden_header}


@app.get("/hidden_path/{hidden_path}")

            )
            assert (
                field_info.default == Undefined or field_info.default == RequiredParam
            ), (
                f"`{field_info.__class__.__name__}` default value cannot be set in"
                f" `Annotated` for {param_name!r}. Set the default value with `=` instead."
            )
            if value is not inspect.Signature.empty:

     */
    Source source() default Source.USER_PROPERTIES;

    /**
     * Specifies the type of the configuration property.
     *
     * @return the fully qualified class name of the property type, defaults to "java.lang.String"
     */
    String type() default "java.lang.String";

    /**
     * Specifies the default value of the configuration property.
     *

	// Default Default logger
	Default = New(log.New(os.Stdout, "\r\n", log.LstdFlags), Config{
		SlowThreshold:             200 * time.Millisecond,
		LogLevel:                  Warn,
		IgnoreRecordNotFoundError: false,
		Colorful:                  true,
	})
	// Recorder logger records running SQL into a recorder instance
	Recorder = traceRecorder{Interface: Default, BeginAt: time.Now()}

            assert param.annotation == router_param.annotation
            assert param.annotation == app_param.annotation
            assert param.default == router_param.default

            super(Lifecycle.CLEAN);
        }
    }

    @Singleton
    @Named(Lifecycle.DEFAULT)
    @SuppressWarnings("unused")
    static class DefaultLifecycleProvider extends BaseLifecycleProvider {
        DefaultLifecycleProvider() {
            super(Lifecycle.DEFAULT);
        }
    }

    @Singleton
    @Named(Lifecycle.SITE)
    @SuppressWarnings("unused")

Então:

```Python
q: str | None = Query(default=None)
```

...torna o parâmetro opcional, com um valor padrão de `None`, o mesmo que:


```Python
q: str | None = None

func (s *Singleton[T]) GetNonBlocking() *T {
	select {
	case <-s.set:
		return s.v
	default:
		return nil
	}
}

// IsSet will return whether the singleton has been set.
func (s *Singleton[T]) IsSet() bool {
	select {
	case <-s.set:
		return true
	default:
		return false
	}
}

// Set the value and unblock all Get requests.

  <p>This is a reference for the Core Extensions descriptor.</p>
  <p>The default location for the Core Extensions descriptor file is <code>${maven.projectBasedir}/.mvn/extensions.xml</code></p>
  ]]></description>

  <defaults>
    <default>
      <key>package</key>
      <value>org.apache.maven.cli.internal.extension.model</value>
    </default>
  </defaults>

  <classes>