This is something that you have to do yourself in your code, and make sure you use those JSON keys.

It's almost the only thing that you have to remember to do correctly yourself, to be compliant with the specifications.

For the rest, **FastAPI** handles it for you.

///

## Update the dependencies

Now we are going to update our dependencies.

//
// It should be always the first / highest HTTP handler.
func setCriticalErrorHandler(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		defer func() {
			if rec := recover(); rec == logger.ErrCritical { // handle
				stack := debug.Stack()
				logger.Error("critical: \"%s %s\": %v\n%s", r.Method, r.URL, rec, string(stack))

Caso contrário, a rota para `/users/{user_id}` coincidiria também para `/users/me`, "pensando" que estaria recebendo o parâmetro `user_id` com o valor de `"me"`.

## Valores predefinidos

Se você tem uma operação de rota que recebe um parâmetro da rota, mas que você queira que esses valores possíveis do parâmetro da rota sejam predefinidos, você pode usar <abbr title="Enumeration">`Enum`</abbr> padrão do Python.

### Criando uma classe `Enum`

        }
        if (patterns.length == 0) {
            return true;
        }

        if (referer == null) {
            return false;
        }
        return Arrays.stream(patterns).anyMatch(p -> p.matcher(referer).matches());
    }

    String getQueryHighlightContentDescriptionFields();

![ReDoc](https://fastapi.tiangolo.com/img/index/index-02-redoc-simple.png)

## Mejora al ejemplo

Ahora modifica el archivo `main.py` para recibir un <abbr title="cuerpo del mensaje HTTP">body</abbr> del `PUT` request.

Declara el body usando las declaraciones de tipo estándares de Python gracias a Pydantic.

```Python hl_lines="2  7-10  23-25"

//
// To put all of this into a simple rule:
//
//	SSE-S3 : ETag == MD5
//	SSE-C  : ETag != MD5
//	SSE-KMS: ETag != MD5
//
// # Encrypted ETags
//
// An S3 implementation has to remember the content MD5 of objects
// in case of SSE-S3. However, storing the ETag of an encrypted
// object in plaintext may reveal some information about the object.
// For example, two objects with the same ETag are identical with

// parse is expected to call any parsing methods that may panic.
// Returns error gathered from recover; nil if no parse errors occurred.
//
// For unexpected panics, calls t.Fatal.
func tryParse(t *testing.T, parse func()) (err error) {
	panicOnError = true
	defer func() {
		panicOnError = false

		e := recover()
		var ok bool
		if err, ok = e.(error); e != nil && !ok {
			t.Fatal(e)
		}
	}()

	parse()

}

// shallowClone will create a shallow clone of the array objects,
// but object metadata will not be cloned.
func (m metaCacheEntriesSorted) shallowClone() metaCacheEntriesSorted {
	// We have value receiver so we already have a copy.
	m.o = m.o.shallowClone()
	return m
}

// fileInfoVersions converts the metadata to FileInfoVersions where possible.
// Metadata that cannot be decoded is skipped.

	}
}

func TestPreparedStmtFromTransaction(t *testing.T) {
	db := DB.Session(&gorm.Session{PrepareStmt: true, SkipDefaultTransaction: true})

	tx := db.Begin()
	defer func() {
		if r := recover(); r != nil {
			tx.Rollback()
		}
	}()
	if err := tx.Error; err != nil {
		t.Errorf("Failed to start transaction, got error %v\n", err)
	}

This is similar to the 200 HTTP status codes (from 200 to 299). Those "200" status codes mean that somehow there was a "success" in the request.

The status codes in the 400 range mean that there was an error from the client.

Remember all those **"404 Not Found"** errors (and jokes)?

## Use `HTTPException`

To return HTTP responses with errors to the client you use `HTTPException`.

### Import `HTTPException`

```Python hl_lines="1"