if err = tx.Save(&user).Error; err != nil {
		t.Fatalf("No error should raise, but got %v", err)
	}

	if err = tx.First(&User{}, "name = ?", "transaction").Error; err != nil {
		t.Fatalf("Should find saved record, but got %v", err)
	}

	user1 := *GetUser("transaction1-1", Config{})

	if err = tx.Save(&user1).Error; err != nil {
		t.Fatalf("No error should raise, but got %v", err)
	}

Они могут объявлять требования к запросу (например заголовки) или другие подзависимости:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[8,13] *}

### Вызов исключений { #raise-exceptions }

Зависимости из dependencies могут вызывать исключения с помощью `raise`, как и обычные зависимости:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[10,15] *}

### Возвращаемые значения { #return-values }

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[8,13] *}

### Exceptions auslösen { #raise-exceptions }

Die Abhängigkeiten können Exceptions `raise`n, genau wie normale Abhängigkeiten:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[10,15] *}

### Rückgabewerte { #return-values }

Pueden declarar requisitos de request (como headers) u otras sub-dependencias:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[8,13] *}

### Lanzar excepciones { #raise-exceptions }

Estas dependencias pueden `raise` excepciones, igual que las dependencias normales:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[10,15] *}

### Valores de retorno { #return-values }

class DictablePet(Pet):
    def __iter__(self):
        return ((k, v) for k, v in self.__dict__.items())


class Unserializable:
    def __iter__(self):
        raise NotImplementedError()

    @property
    def __dict__(self):
        raise NotImplementedError()


class RoleEnum(Enum):
    admin = "admin"
    normal = "normal"


class ModelWithConfig(BaseModel):
    role: Optional[RoleEnum] = None

Dependências podem declarar requisitos de requisições (como cabeçalhos) ou outras subdependências:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[8,13] *}

### Levantar exceções { #raise-exceptions }

Essas dependências podem `raise` exceções, da mesma forma que dependências comuns:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[10,15] *}

### Valores de retorno { #return-values }

    alias: Optional[str] = None,
    mode: Literal["validation", "serialization"] = "validation",
    version: Literal["1", "auto"] = "auto",
) -> ModelField:
    if annotation_is_pydantic_v1(type_):
        raise PydanticV1NotSupportedError(
            "pydantic.v1 models are no longer supported by FastAPI."
            f" Please update the response model {type_!r}."
        )
    class_validators = class_validators or {}

### Siempre `raise` en Dependencias con `yield` y `except` { #always-raise-in-dependencies-with-yield-and-except }

Si capturas una excepción en una dependencia con `yield`, a menos que estés lanzando otra `HTTPException` o similar, **deberías volver a lanzar la excepción original**.

Puedes volver a lanzar la misma excepción usando `raise`:

        self.open = True

    def __iter__(self) -> Generator[str, None, None]:
        for item in self.data:
            if self.open:
                yield item
            else:
                raise ValueError("Session closed")


@contextmanager
def acquire_session() -> Generator[Session, None, None]:
    session = Session()
    try:
        yield session
    finally:
        session.open = False

    def __class__(self):
        return uuid.UUID

    @property
    def __dict__(self):
        """Spoof a missing __dict__ by raising TypeError, this is how
        asyncpg.pgroto.pgproto.UUID behaves"""
        raise TypeError("vars() argument must have __dict__ attribute")


def test_pydanticv2():
    from pydantic import field_serializer

    app = FastAPI()

    @app.get("/fast_uuid")
    def return_fast_uuid():