assertFalse(registration.isExpired(60000));

        // Wait a bit to ensure some time has passed
        Thread.sleep(50);
        // Should be expired with very short timeout (shorter than sleep time)
        assertTrue(registration.isExpired(10));
    }

    @Test
    void testStateTransitions() {

    end
```

/// tip

It's very common in Python packages to try the best to **avoid breaking changes** in **new versions**, but it's better to be safe, and install newer versions intentionally and when you can run the tests to check everything is working correctly.

///

     * and then a list is built. These exceptions are usually thrown in "fatal" cases (and usually prevent Maven
     * from starting), and these exceptions may end up very early on output.
     *
     * @param message the base message to enhance
     * @param problems the collection of problems to include in the message
     * @return a formatted message including details of all problems
     */

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[22] *}

/// tip

All this might seem contrived. And it might not be very clear how is it useful yet.

These examples are intentionally simple, but show how it all works.

In the chapters about security, there are utility functions that are implemented in this same way.

///

## Upgrading the FastAPI versions { #upgrading-the-fastapi-versions }

You should add tests for your app.

With **FastAPI** it's very easy (thanks to Starlette), check the docs: [Testing](../tutorial/testing.md){.internal-link target=_blank}

Containers (mainly Linux containers) are a very **lightweight** way to package applications including all their dependencies and necessary files while keeping them isolated from other containers (other applications or components) in the same system.

    attributes:
      label: "What did you see happen?"
      description: Command invocations and their associated output, functions with their arguments and return results, full stacktraces for panics (upload a file if it is very long), etc. Prefer copying text output over using screenshots.
    validations:
      required: true

  - type: textarea
    id: expected-behavior
    attributes:
      label: "What did you expect to see?"

    val maxParallelForks: Int = 4,
) {
    // Include cross version tests, these take care of selecting a very small set of versions to cover when run as part of this stage, including the current version
    QUICK(true, true, true, 120, 4),

    // Include cross version tests, these take care of selecting a very small set of versions to cover when run as part of this stage, including the current version
    PLATFORM(true, true, true),

        // Verify that the exception has serialVersionUID field (won't compile if not present)
        assertTrue(exception instanceof java.io.Serializable);
    }

    public void test_longMessage() {
        // Test with very long message
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 1000; i++) {
            sb.append("Long message part ").append(i).append(" ");
        }

        // which implements Serializable
        assertTrue(exception instanceof java.io.Serializable);
    }

    public void test_longMessageHandling() {
        // Test with very long message
        StringBuilder longMessage = new StringBuilder();
        for (int i = 0; i < 1000; i++) {
            longMessage.append("Storage error ").append(i).append(" ");
        }