Nesse cenário, se você precisa manipular essa exceção de modo global com o FastAPI, você pode adicionar um manipulador de exceção customizada com `@app.exception_handler()`.

{* ../../docs_src/handling_errors/tutorial003_py39.py hl[5:7,13:18,24] *}

```

`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`
* `Tuple`
* `Set`
* `Dict`
* `Optional`
* ...등등

위와 같은 타입은 **Generic(제네릭) 타입** 혹은 **Generics(제네릭스)**라고 불립니다.

### 타입으로서의 클래스

변수의 타입으로 클래스를 선언할 수도 있습니다.

이름(name)을 가진 `Person` 클래스가 있다고 해봅시다.

 */

package com.google.common.collect.testing.testers;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.AbstractMapTester;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code size()} operations on a map. Can't be invoked directly;
 * please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author George van den Driessche
 */
@GwtCompatible

  What is it?
  -----------

  Maven is a software project management and comprehension tool. Based on
  the concept of a Project Object Model (POM), Maven can manage a project's
  build, reporting and documentation from a central piece of information.

  Documentation
  -------------

  The most up-to-date documentation can be found at https://maven.apache.org/.

  Release Notes
  -------------

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.model.building;

/**
 * Assists in firing events from a generic method by abstracting from the actual callback method to be called on the
 * listener.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@Deprecated(since = "4.0.0")

//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package lifecycle

import (
	"fmt"
)

// Error is the generic type for any error happening during tag
// parsing.
type Error struct {
	err error
}

// Errorf - formats according to a format specifier and returns
// the string as a value that satisfies error of type tagging.Error

//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package versioning

import (
	"fmt"
)

// Error is the generic type for any error happening during tag
// parsing.
type Error struct {
	err error
}

// Errorf - formats according to a format specifier and returns
// the string as a value that satisfies error of type tagging.Error

import com.google.common.collect.testing.WrongType;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code contains()} operations on a collection. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author Kevin Bourrillion

import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code retainAll} operations on a list. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.ListTestSuiteBuilder}.
 *
 * @author Chris Povirk
 */
@GwtCompatible

import org.apache.maven.api.annotations.Nonnull;

/**
 * Defines the contract for a component responsible for invoking a Maven application
 * using the information provided in an {@link InvokerRequest}. This interface is central
 * to the construction and invocation of Maven commands and builds, and it fully parses arguments.
 *
 * <p>The Invoker is designed to be flexible, allowing for different implementations