```Python
old_dict = {
    "old key": "old value",
    "second old key": "second old value",
}
new_dict = {**old_dict, "new key": "new value"}
```

Here, `new_dict` will contain all the key-value pairs from `old_dict` plus the new key-value pair:

```Python
{
    "old key": "old value",
    "second old key": "second old value",
    "new key": "new value",
}
```

* Show a **clear error** for the client when the data is not valid
* **Document** the parameter in the OpenAPI schema *path operation* (so it will show up in the **automatic docs UI**)

## Alternative (old): `Query` as the default value { #alternative-old-query-as-the-default-value }

    * `Body()`
    * `File()`
    * `Form()`

/// info

This old OpenAPI-specific `examples` parameter is now `openapi_examples` since FastAPI `0.103.0`.

///

### JSON Schema's `examples` field { #json-schemas-examples-field }

     */
    private void performMaintenanceTasks() {
        // Clean up old failure records
        long now = System.currentTimeMillis();
        lastFailureTimes.entrySet().removeIf(entry -> now - entry.getValue() > FAILURE_RECOVERY_TIME * 2);

        // Clean up old consecutive failure counters
        consecutiveFailures.entrySet().removeIf(entry -> {
            String key = entry.getKey();

        if (keyManager != null) {
            // Rotate keys in SecureKeyManager
            String encKeyId = sessionId + "-enc";
            String decKeyId = sessionId + "-dec";

            // Remove old keys
            keyManager.removeSessionKey(encKeyId);
            keyManager.removeSessionKey(decKeyId);

            // Store new keys
            keyManager.storeSessionKey(encKeyId, newEncryptionKey, "AES");

* Response payloads.

You would also have **inline errors** for everything.

And whenever you update the backend code, and **regenerate** the frontend, it would have any new *path operations* available as methods, the old ones removed, and any other change would be reflected on the generated code. 🤓

Create a PassLib "context". This is what will be used to hash and verify passwords.

/// tip

The PassLib context also has functionality to use different hashing algorithms, including deprecated old ones only to allow verifying them, etc.

For example, you could use it to read and verify passwords generated by another system (like Django) but hash any new passwords with a different algorithm like Bcrypt.

        byte[] encrypted2 = context.encryptMessage(plaintext2, 2L);
        byte[] decrypted2 = context.decryptMessage(encrypted2);
        assertArrayEquals(plaintext2, decrypted2);

        // Old encrypted data would need old keys to decrypt (not tested here)

        context.close();
    }

    @Test
    @DisplayName("Should rotate keys with SecureKeyManager")

But then you have to call "that method that converts the first letter to upper case".

Was it `upper`? Was it `uppercase`? `first_uppercase`? `capitalize`?

Then, you try with the old programmer's friend, editor autocompletion.

You type the first parameter of the function, `first_name`, then a dot (`.`) and then hit `Ctrl+Space` to trigger the completion.

But, sadly, you get nothing useful:

<div class="termy">

```console
$ cd ~/code/prisoner-of-azkaban

// You don't need to be in the old directory to deactivate, you can do it wherever you are, even after going to the other project 😎
$ deactivate

// Activate the virtual environment in prisoner-of-azkaban/.venv 🚀
$ source .venv/bin/activate