"email-validator not installed, email fields will be treated as str.\n"
                "To install, run: pip install email-validator"
            )
            return str(v)

        @classmethod
        def _validate(cls, __input_value: Any, _: Any) -> str:
            logger.warning(
                "email-validator not installed, email fields will be treated as str.\n"
                "To install, run: pip install email-validator"

   */
  public static <E extends @Nullable Object> void assertMultisetIsUnmodifiable(
      Multiset<E> multiset, E sampleElement) {
    Multiset<E> copy = LinkedHashMultiset.create(multiset);
    assertCollectionsAreEquivalent(multiset, copy);

    // Multiset is a collection, so we can use all those tests.
    assertCollectionIsUnmodifiable(multiset, sampleElement);

        assertArgumentNotNull("props", props);
        assertArgumentNotNull("file", file);
        assertArgumentNotEmpty("encoding", encoding);

        final Reader reader = ReaderUtil.create(file, encoding);

        try {
            props.load(reader);
        } catch (final IOException e) {
            throw new IORuntimeException(e);
        } finally {
            CloseableUtil.close(reader);

        this.delegate = requireNonNull(delegate);
        if (queueSize < 1 || batchMaxSize < 1) {
            throw new IllegalArgumentException("Queue and batch sizes must be greater than 1");
        }
        this.batchMaxSize = batchMaxSize;
        this.blockOnLastEvent = blockOnLastEvent;

        this.eventQueue = new ArrayBlockingQueue<>(queueSize);

     */
    @Override
    public TransformerContext initialize(ModelBuildingRequest request, ModelProblemCollector collector) {
        // We must assume the TransformerContext was created using this.newTransformerContextBuilder()
        DefaultModelProblemCollector problems = (DefaultModelProblemCollector) collector;
        return new TransformerContext() {

            @Override

	if err != nil {
		t.Fatalf("Failed to marshal versioning config: %v", err)
	}

	bucket := "bucket"
	obj := "obj-1"
	now := time.Now()
	meta := BucketMetadata{
		Name:                      bucket,
		Created:                   now,
		LifecycleConfigXML:        lcXML,
		VersioningConfigXML:       vcfgXML,
		VersioningConfigUpdatedAt: now,
		LifecycleConfigUpdatedAt:  now,
		lifecycleConfig:           &lc,

---

## Install FastAPI

The first step is to install FastAPI.

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then **install FastAPI**:

<div class="termy">

```console
$ pip install "fastapi[standard]"

---> 100%
```

                        rr.getPolicy(true).getUpdatePolicy(),
                        rr.getPolicy(false).getChecksumPolicy());

            } catch (Exception e) {
                throw new RuntimeException("Unable to create repository", e);
            }
        } else {
            // TODO
            throw new UnsupportedOperationException("Not yet implemented");
        }
    }

            pass  # pragma: no cover
    assert e.value.code == status.WS_1000_NORMAL_CLOSURE


def websocket_middleware(middleware_func):
    """
    Helper to create a Starlette pure websocket middleware
    """

    def middleware_constructor(app):
        @functools.wraps(app)
        async def wrapped_app(scope, receive, send):
            if scope["type"] != "websocket":

      return object : DeferredSocketAdapter.Factory {
        override fun matchesSocket(sslSocket: SSLSocket): Boolean = sslSocket.javaClass.name.startsWith("$packageName.")

        override fun create(sslSocket: SSLSocket): SocketAdapter {
          return build(sslSocket.javaClass)
        }
      }
    }
  }