- Adding a set of debugging endpoints under prefix "/debug/flowcontrol/*" for dumping internal states of flow-control system with different granularity. ([#90967](https://github.com/kubernetes/kubernetes/pull/90967), [@yue9944882](https://github.com/yue9944882)) [SIG API Machinery]

  /** True if this connect was canceled; typically because it lost a race. */
  @Volatile private var canceled = false

  // These properties are initialized by connect() and never reassigned.

  /** The low-level TCP socket. */
  private var rawSocket: JavaNetSocket? = null

  /**
   * The application layer socket. Either an [SSLSocket] layered over [rawSocket], or [rawSocket]
   * itself if this connection does not use SSL.

import org.junit.jupiter.api.Timeout
import org.junit.jupiter.api.extension.RegisterExtension
import org.junit.runner.Description
import org.junit.runners.model.Statement

@Suppress("deprecation")
@Timeout(30)
@Tag("Slow")
class MockWebServerTest {
  @RegisterExtension
  var platform = PlatformRule()
  private val server = MockWebServer()

  @BeforeEach
  fun setUp() {
    server.start()
  }

  @AfterEach

    try {
      constructor = type.getConstructor();
    } catch (NoSuchMethodException e) {
      return arbitraryConstantInstanceOrNull(type);
    }
    constructor.setAccessible(true); // accessibility check is too slow
    try {
      return constructor.newInstance();
    } catch (InstantiationException | IllegalAccessException impossible) {
      throw new AssertionError(impossible);
    } catch (InvocationTargetException e) {

  final boolean threadStarted;

  /** Constructs a new queue. */
  public FinalizableReferenceQueue() {
    // We could start the finalizer lazily, but I'd rather it blow up early.
    queue = new ReferenceQueue<>();
    frqRef = new PhantomReference<>(this, queue);
    boolean threadStarted = false;
    try {
      startFinalizer.invoke(null, FinalizableReference.class, queue, frqRef);

### Creating the `Settings` only once with `lru_cache` { #creating-the-settings-only-once-with-lru-cache }

Reading a file from disk is normally a costly (slow) operation, so you probably want to do it only once and then reuse the same settings object, instead of reading it for each request.

But every time we do:

```Python
Settings()
```

import okio.Socket
import okio.buffer
import okio.inMemorySocketPair
import org.junit.jupiter.api.AfterEach
import org.junit.jupiter.api.BeforeEach
import org.junit.jupiter.api.Tag
import org.junit.jupiter.api.Test

@Tag("Slow")
class RealWebSocketTest {
  // NOTE: Fields are named 'client' and 'server' for cognitive simplicity. This differentiation has
  // zero effect on the behavior of the WebSocket API which is why tests are only written once

        ArtifactResolutionResult result = resolve(request);

        // We have collected all the problems so let's mimic the way the old code worked and just blow up right here.
        // That's right lets just let it rip right here and send a big incomprehensible blob of text at unsuspecting
        // users. Bad dog!

        resolutionErrorHandler.throwErrors(request, result);

    assertTrue(enormous instanceof RegularContiguousSet);
    // We can't use reserializeAndAssert because it calls hashCode, which is enormously slow.
    ContiguousSet<Integer> enormousReserialized = reserialize(enormous);
    assertEquals(enormous, enormousReserialized);
  }

  private static final DiscreteDomain<Integer> UNBOUNDED_THROWING_DOMAIN =

    List<String> list = ImmutableList.of("a", "b");
    Iterator<String> iterator = skip(list, 2).iterator();
    assertThrows(UnsupportedOperationException.class, () -> iterator.remove());
  }

  @GwtIncompatible // slow (~35s)
  public void testSkip_iterator() {
    new IteratorTester<Integer>(
        5, MODIFIABLE, newArrayList(2, 3), IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override