### Modern Java 21 Support
- **Pattern Matching** - Leverages modern Java pattern matching for efficient type checking and conversion
- **Switch Expressions** - Optimized implementations using switch expressions for better performance
- **Sequenced Collections** - Full support for Java 21 sequenced collections API with dedicated utility methods

## Add regular expressions { #add-regular-expressions }

You can define a <abbr title="A regular expression, regex or regexp is a sequence of characters that define a search pattern for strings.">regular expression</abbr> `pattern` that the parameter should match:

{* ../../docs_src/query_params_str_validations/tutorial004_an_py310.py hl[11] *}

This specific regular expression pattern checks that the received parameter value:

        violations = validator.validate(bean);
        assertTrue(violations.isEmpty());
    }

    // Test validation with invalid cron expressions
    public void test_invalidCronExpressions() {
        TestBean bean = new TestBean();

        // Test invalid cron expression
        bean.setCronExpression("invalid");
        Set<ConstraintViolation<TestBean>> violations = validator.validate(bean);

    @Nonnull
    Optional<Boolean> infer();

    /**
     * Should fix Maven 4 compatibility issues in POMs.
     * This includes fixing unsupported combine attributes, duplicate dependencies,
     * unsupported expressions, and other Maven 4 validation issues.
     *
     * @return an {@link Optional} containing the boolean value {@code true} if specified, or empty
     */
    @Nonnull
    Optional<Boolean> model();

    /**

Create functions with a name that starts with `test_` (this is standard `pytest` conventions).

Use the `TestClient` object the same way as you do with `httpx`.

Write simple `assert` statements with the standard Python expressions that you need to check (again, standard `pytest`).

{* ../../docs_src/app_testing/tutorial001.py hl[2,12,15:18] *}

/// tip

Notice that the testing functions are normal `def`, not `async def`.

        Object result = scriptEngine.evaluate(template, paramMap);
        assertEquals("Price: $100 (with 20% off)", result);
    }

    // Test evaluate method with nested expressions
    public void test_evaluate_withNestedExpressions() {
        String template = "${level1.level2.value}";
        Map<String, Object> paramMap = new HashMap<>();
        Map<String, Object> level2 = new HashMap<>();

def get_sequential_burgers(number: int):
    # Do some sequential stuff to create the burgers
    return burgers
```

With `async def`, Python knows that, inside that function, it has to be aware of `await` expressions, and that it can "pause" ⏸ the execution of that function and go do something else 🔀 before coming back.

When you want to call an `async def` function, you have to "await" it. So, this won't work:

```Python

def get_sequential_burgers(number: int):
    # Opérations asynchrones pour créer les burgers
    return burgers
```

Avec `async def`, Python sait que dans cette fonction il doit prendre en compte les expressions `await`, et qu'il peut mettre en pause ⏸ l'exécution de la fonction pour aller faire autre chose 🔀 avant de revenir.

Pour appeler une fonction définie avec `async def`, vous devez utiliser `await`. Donc ceci ne marche pas :

     * the names and the server does not have to return all directory
     * entries.
     * <p>
     * The wildcard expression may consist of two special meta
     * characters in addition to the normal filename characters. The '*'
     * character matches any number of characters in part of a name. If
     * the expression begins with one or more '?'s then exactly that
     * many characters will be matched whereas if it ends with '?'s

     * the names and the server does not have to return all directory
     * entries.
     * <p>
     * The wildcard expression may consist of two special meta
     * characters in addition to the normal filename characters. The '*'
     * character matches any number of characters in part of a name. If
     * the expression begins with one or more '?'s then exactly that
     * many characters will be matched whereas if it ends with '?'s