// This is because the logging code installs a shutdown hook of its
                  // own. See Cleaner class inside {@link LogManager}.
                  service.awaitTermination(terminationTimeout, timeUnit);
                } catch (InterruptedException ignored) {
                  // We're shutting down anyway, so just ignore.
                }
              }));
    }

    @VisibleForTesting

    double twoToThe53 = Math.pow(2, 53);
    // the representable doubles are 2^53 and 2^53 + 2.
    // 2^53+1 is halfway between, so HALF_UP will go up and HALF_DOWN will go down.
    new RoundToDoubleTester(BigDecimal.valueOf((1L << 53) + 1))
        .setExpectation(twoToThe53, DOWN, FLOOR, HALF_DOWN, HALF_EVEN)
        .setExpectation(Math.nextUp(twoToThe53), CEILING, UP, HALF_UP)
        .roundUnnecessaryShouldThrow()
        .test();
  }

    double twoToThe53 = Math.pow(2, 53);
    // the representable doubles are 2^53 and 2^53 + 2.
    // 2^53+1 is halfway between, so HALF_UP will go up and HALF_DOWN will go down.
    new RoundToDoubleTester(BigInteger.valueOf((1L << 53) + 1))
        .setExpectation(twoToThe53, DOWN, FLOOR, HALF_DOWN, HALF_EVEN)
        .setExpectation(Math.nextUp(twoToThe53), CEILING, UP, HALF_UP)
        .roundUnnecessaryShouldThrow()
        .test();
  }

# Sub Applications - Mounts { #sub-applications-mounts }

If you need to have two independent FastAPI applications, with their own independent OpenAPI and their own docs UIs, you can have a main app and "mount" one (or more) sub-application(s).

## Mounting a **FastAPI** application { #mounting-a-fastapi-application }

Follow your cloud provider's guides to deploy FastAPI apps with them. 🤓

## Deploy your own server { #deploy-your-own-server }

  val request3 = server.takeRequest()
  assertEquals("/v1/chat/messages/3", request3.url.encodedPath)

  // Shut down the server. Instances cannot be reused.
  server.close()
}
```

Your unit tests might move the `server` into a field so you can shut it down
from your test's `tearDown()`.

### API

#### MockResponse

To use, first add this library as a test dependency:

```
testImplementation("com.squareup.okhttp3:mockwebserver3-junit5:5.3.0")
```

Annotate fields in test classes with `@StartStop`. The server will be started and shut down
automatically.

```
class MyTest {

  @StartStop
  public final MockWebServer server = new MockWebServer();

  @Test
  void test() {
    ...
  }
}
```

Requirements
------------

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

```
@Rule public final MockWebServerRule serverRule = new MockWebServerRule();
```

The `serverRule` field has a `server` field. It is an instance of `MockWebServer`. That instance
will be shut down automatically after the test runs.

For Kotlin, the `@JvmField` annotation is also necessary:

```
@JvmField @Rule val serverRule = MockWebServerRule()

All the **logic** about how to register the URLs for webhooks and the code to actually send those requests is up to you. You write it however you want to in **your own code**.

## Documenting webhooks with **FastAPI** and OpenAPI { #documenting-webhooks-with-fastapi-and-openapi }