/*
   * AbstractCollection fails the retainAll(null) test when the subject
   * collection is empty, but we'd still like to test retainAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.
   */

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRetainAll_nullCollectionReferenceEmptySubject() {
    try {

{!../../docs_src/app_testing/tutorial001.py!}
```

/// tip

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

And the calls to the client are also normal calls, not using `await`.

This allows you to use `pytest` directly without complications.

///

/// note | "Technical Details"

You could also use `from starlette.testclient import TestClient`.

Traditional retrieval of objects is always as whole entities, i.e GetObject for a 5 GiB object, will always return 5 GiB of data. S3 Select API allows us to retrieve a subset of data by using simple SQL expressions. By using Select API to retrieve only the data needed by the application, drastic performance improvements can be achieved.

   * before less urgent messages and close frames. For example it's possible that a caller will
   * enqueue messages followed by pongs, but this sends pongs followed by messages. Pongs are always
   * written in the order they were enqueued.
   *
   * If a frame cannot be sent - because there are none enqueued or because the web socket is not

}

func getFilterType(filters []*listener.Filter) string {
	for _, filter := range filters {
		if filter.Name == HTTPListener {
			httpProxy := &hcm.HttpConnectionManager{}
			// Allow Unmarshal to work even if Envoy and istioctl are different
			filter.GetTypedConfig().TypeUrl = "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager"

    assertFalse(inputFuture.isCancelled());
    assertFalse(outputFuture.isCancelled());
    assertThrows(CancellationException.class, () -> resultFuture.get());

    funcCompletionLatch.countDown(); // allow the function to complete
    assertThrows(CancellationException.class, () -> outputFuture.get());
  }

  public void testFutureCancelAfterCompletion() throws Exception {
    inputFuture.set(VALID_INPUT_DATA);

    assertFalse(inputFuture.isCancelled());
    assertFalse(outputFuture.isCancelled());
    assertThrows(CancellationException.class, () -> resultFuture.get());

    funcCompletionLatch.countDown(); // allow the function to complete
    assertThrows(CancellationException.class, () -> outputFuture.get());
  }

  public void testFutureCancelAfterCompletion() throws Exception {
    inputFuture.set(VALID_INPUT_DATA);

        // global-level settings somewhere other than ${user.home} and ${maven.home},
        // respectively. Using a simple replacement of these patterns will allow them
        // to specify the absolute path to these files in a customized components.xml
        // file. Ideally, we'd do full pattern-evaluation against the sysprops, but this

    server.enqueue(
      MockResponse.Builder()
        .addHeader("Allow: GET, HEAD")
        .addHeader("Last-Modified: " + formatDate(-1, TimeUnit.HOURS))
        .addHeader("Cache-Control: max-age=0")
        .body("A")
        .build(),
    )
    server.enqueue(
      MockResponse.Builder()
        .addHeader("Allow: GET, HEAD, PUT")
        .code(HttpURLConnection.HTTP_NOT_MODIFIED)

### Remotely Inspecting backend data