We are going to start from where we left in the previous chapter and increment it.

## About JWT

JWT means "JSON Web Tokens".

It's a standard to codify a JSON object in a long dense string without spaces. It looks like this:

```
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
```

        that can triggerred by `multiply_linear_by_lr` allowing a learning rate
        of zero.

### `tf.data`:

*   `tf.data.experimental.dense_to_ragged_batch` works correctly with tuples.
*   `tf.data.experimental.dense_to_ragged_batch` to output variable ragged rank.
*   `tf.data.experimental.cardinality` is now a method on `tf.data.Dataset`.

You probably wouldn't want to take your crush 😍 with you to do errands at the bank 🏦.

### Burger Conclusion

In this scenario of "fast food burgers with your crush", as there is a lot of waiting 🕙, it makes a lot more sense to have a concurrent system ⏸🔀⏯.

This is the case for most of the web applications.

Many, many users, but your server is waiting 🕙 for their not-so-good connection to send their requests.

"_Si vous cherchez à apprendre un **framework moderne** pour créer des APIs REST, regardez **FastAPI** [...] C'est rapide, facile à utiliser et à apprendre [...]_"

"_Nous sommes passés à **FastAPI** pour nos **APIs** [...] Je pense que vous l'aimerez [...]_"

            // `Foo.Bar` is definitely not a property access - otherwise it would have had its own FIR.
            // So, it does not make sense to try to resolve such parts of qualifiers as KtCall
            if ((psi as? KtExpression)?.getPossiblyQualifiedCallExpression() == null) {
                return null
            }

}

// A StatefulSetSpec is the specification of a StatefulSet.
message StatefulSetSpec {
  // replicas is the desired number of replicas of the given Template.
  // These are replicas in the sense that they are instantiations of the
  // same Template, but individual replicas also have a consistent identity.
  // If unspecified, defaults to 1.
  // TODO: Consider a rename of this field.
  // +optional

  //  * If Type is Added or Modified: the new state of the object.
  //  * If Type is Deleted: the state of the object immediately before deletion.
  //  * If Type is Error: *Status is recommended; other types may make sense
  //    depending on context.
  optional k8s.io.apimachinery.pkg.runtime.RawExtension object = 2;

### Tags with Enums

If you have a big application, you might end up accumulating **several tags**, and you would want to make sure you always use the **same tag** for related *path operations*.

In these cases, it could make sense to store the tags in an `Enum`.

**FastAPI** supports that the same way as with plain strings:

```Python hl_lines="1  8-10  13  18"
{!../../../docs_src/path_operation_configuration/tutorial002b.py!}
```

    ```Python hl_lines="68-69  81"
    {!> ../../../docs_src/websockets/tutorial002.py!}
    ```

!!! info
    As this is a WebSocket it doesn't really make sense to raise an `HTTPException`, instead we raise a `WebSocketException`.

And if there's any other style or consistency need, I'll ask directly for that, or I'll add commits on top with the needed changes.

### Check the code

* Check and read the code, see if it makes sense, **run it locally** and see if it actually solves the problem.

* Then **comment** saying that you did that, that's how I will know you really checked it.

!!! info