* such custom interfaces directly; they are implemented only in subclasses. Therefore, forwarding
 * {@code equals} would break symmetry, as the forwarding object might consider itself equal to the
 * object being tested, but the reverse could not be true. This behavior is consistent with the
 * JDK's collection wrappers, such as {@link java.util.Collections#unmodifiableCollection}. Use an

It might also help avoid confusion for new developers that see an unused parameter in your code and could think it's unnecessary.

///

/// info

In this example we use invented custom headers `X-Key` and `X-Token`.

But in real cases, when implementing security, you would get more benefits from using the integrated [Security utilities (the next chapter)](../security/index.md){.internal-link target=_blank}.

---

 *     thingToRun.run(); // say this may throw an exception, but you want to
 *                       // always run all thingsToRun
 *   }
 * }
 * </pre>
 *
 * <p>This is what the code would become:
 *
 * <pre>
 * void runManyThings({@literal List<ThingToRun>} thingsToRun) {
 *   {@literal List<Exception>} exceptions = Lists.newArrayList();
 *   for (ThingToRun thingToRun : thingsToRun) {
 *     try {

      // It is possible due to races that we are currently in the expected state even though we
      // timed out. e.g. if we weren't event able to grab the lock within the timeout we would never
      // even check the guard. I don't think we care too much about this use case but it could lead
      // to a confusing error message.
      throw new TimeoutException("Timed out waiting for " + this + " to reach the RUNNING state.");
    }
  }

            transport.release();
            assertEquals(beforeRelease - 1, transport.getUsageCount());
        }

        @Test
        @DisplayName("release should throw exception when usage count would go negative")
        void shouldThrowOnNegativeUsage() {
            transport.release(); // Make it 0
            assertThrows(RuntimeCIFSException.class, transport::release);
        }

        @Test

To achieve this, the `:80`-backend must have a list of "allowed origins".

In this case, the list would have to include `http://localhost:8080` for the `:8080`-frontend to work correctly.

## Wildcards { #wildcards }

It's also possible to declare the list as `"*"` (a "wildcard") to say that all are allowed.

│   └── main.py
```

In the file `main.py` you have your **FastAPI** app:


{* ../../docs_src/app_testing/main.py *}

### Testing file { #testing-file }

Then you could have a file `test_main.py` with your tests. It could live on the same Python package (the same directory with a `__init__.py` file):

``` hl_lines="5"
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

    /*
     * For example, if concentration=2.0, the following takes the square root of
     * the uniformly-distributed random integer, then truncates any fractional
     * part, so higher integers would appear (in this case linearly) more often
     * than lower ones.
     */
    return (int) Math.pow(a, 1.0 / concentration);
  }

  @AfterExperiment
  void tearDown() {
    double req = requests.get();

        resp.received = true;

        session.transport(); // initialise transport

        // Mock the sessionSetup behavior to avoid actual network calls
        // The sessionSetup method would normally send authentication messages
        // Only mark the sessionSetup response as received, not the actual request/response
        doAnswer(invocation -> {
            ServerMessageBlock request = invocation.getArgument(0);