that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the 'X-' prefix</a>.

But if you have custom headers that you want a client in a browser to be able to see, you need to add them to your CORS configurations (read more in [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), using the parameter `expose_headers` documented in <a href="https://www....

        What is the problem, question, or error?

        Write a short description telling me what you are doing, what you expect to happen, and what is currently happening.
      placeholder: |
        * Open the browser and call the endpoint `/`.
        * It returns a JSON with `{"Hello": "World"}`.
        * But I expected it to return `{"Hello": "Sara"}`.
    validations:
      required: true
  - type: dropdown
    id: os

Dies wäre die parallele äquivalente Geschichte für Hamburger. 🍔

Für ein „realeres“ Beispiel hierfür, stellen Sie sich eine Bank vor.

Bis vor kurzem hatten die meisten Banken mehrere Kassierer 👨‍💼👨‍💼👨‍💼👨‍💼 und eine große Warteschlange 🕙🕙🕙🕙🕙🕙🕙🕙.

Alle Kassierer erledigen die ganze Arbeit mit einem Kunden nach dem anderen 👨‍💼⏯.

Und man muss lange in der Schlange warten 🕙 sonst kommt man nicht an die Reihe.

			if ok, mode := hasReturning(db, supportReturning); ok {
				if rows, err := db.Statement.ConnPool.QueryContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...); db.AddError(err) == nil {
					dest := db.Statement.Dest
					db.Statement.Dest = db.Statement.ReflectValue.Addr().Interface()
					gorm.Scan(rows, db, mode)
					db.Statement.Dest = dest
					db.AddError(rows.Close())

					if db.Statement.Result != nil {

<div class="termy">

```console
$ fastapi dev main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

Abrar seu browser em: <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

Lá você pode definir:

* O "Item ID", usado na rota.
* O "Token" usado como um parâmetro de consulta.

       * columns in the first row, the columns in the second row, etc. If a column Comparator is
       * provided but a row Comparator isn't, cellSet() iterates across the rows in the first
       * column, the rows in the second column, etc.
       */
      Comparator<Cell<R, C, V>> comparator =
          (Cell<R, C, V> cell1, Cell<R, C, V> cell2) -> {
            int rowCompare =

<img src="/img/tutorial/sub-applications/image02.png">

If you try interacting with any of the two user interfaces, they will work correctly, because the browser will be able to talk to each specific app or sub-app.

### Technical Details: `root_path` { #technical-details-root-path }

	// accordingly. Client receives a HTTP error for invalid/unsupported
	// signatures.
	//
	// Validates all incoming requests to have a valid date header.
	setAuthMiddleware,
	// Redirect some pre-defined browser request paths to a static location
	// prefix.
	setBrowserRedirectMiddleware,
	// Adds 'crossdomain.xml' policy middleware to serve legacy flash clients.
	setCrossDomainPolicyMiddleware,

```mermaid
graph LR

browser("Navegador")
proxy["Proxy en http://0.0.0.0:9999/api/v1/app"]
server["Servidor en http://127.0.0.1:8000/app"]

browser --> proxy
proxy --> server
```

/// tip | Consejo

Caching
=======

OkHttp implements an optional, off by default, Cache. OkHttp aims for RFC correct and
pragmatic caching behaviour, following common real-world browser like Firefox/Chrome and 
server behaviour when ambiguous.

# Basic Usage

```kotlin
  private val client: OkHttpClient = OkHttpClient.Builder()
      .cache(Cache(
          directory = File(application.cacheDir, "http_cache"),
          // $0.05 worth of phone storage in 2020