if (closed) return
    closed = true

    if (!started) return // Nothing to shut down.
    val serverSocket = this.serverSocket ?: return // If this is null, start() must have failed.

    // Cause acceptConnections() to break out.
    serverSocket.closeQuietly()

    // Await shutdown.
    for (queue in taskRunner.activeQueues()) {
      if (!queue.idleLatch().await(5, TimeUnit.SECONDS)) {

    This could have corrupted requests where multiple headers had the same name,
    as in cookies.
 *  Fix: Reject bad characters in the URL hostname. Previously characters like
    `\0` would cause a late crash when building the request.
 *  Fix: Allow interceptors to change the request method.
 *  Fix: Don’t use the request's `User-Agent` or `Proxy-Authorization` when

/**
 * Base class for JSR166 Junit TCK tests. Defines some constants, utility methods and classes, as
 * well as a simple framework for helping to make sure that assertions failing in generated threads
 * cause the associated test that generated them to itself fail (which JUnit does not otherwise
 * arrange). The rules for creating such tests are:
 *
 * <ol>

     * log n) on average.
     *
     * <p>The online hash flooding detecting in RegularSetBuilderImpl.add can detect e.g. many
     * exactly matching hash codes, which would cause construction to take O(n^2), but can't detect
     * e.g. hash codes adversarially designed to go into ascending table locations, which keeps
     * construction O(n) (as desired) but then can have O(n) queries later.
     *

			if configRetriableErrors(err) {
				retryInterval := time.Duration(r.Float64() * float64(time.Second))
				logger.Info("Waiting for all MinIO IAM sub-system to be initialized.. possible cause (%v) (retrying in %s)", err, retryInterval)
				time.Sleep(retryInterval)
				continue
			}
			iamLogIf(ctx, fmt.Errorf("IAM sub-system is partially initialized, unable to write the IAM format: %w", err), logger.WarningKind)

   * Executor#execute execute}, as in {@link CallerRunsPolicy}.
   *
   * <p>This executor is appropriate for tasks that are lightweight and not deeply chained.
   * Inappropriate {@code directExecutor} usage can cause problems, and these problems can be
   * difficult to reproduce because they depend on timing. For example:
   *
   * <ul>
   *   <li>When a {@code ListenableFuture} listener is registered to run under {@code

     * they are no longer referenced.
     */
    final Map<LockGraphNode, ExampleStackTrace> allowedPriorLocks =
        new MapMaker().weakKeys().makeMap();

    /**
     * The map tracking lock nodes that can cause a lock acquisition cycle if acquired before this
     * node.
     */
    final Map<LockGraphNode, PotentialDeadlockException> disallowedPriorLocks =
        new MapMaker().weakKeys().makeMap();

        verifyBarPass(method, bar); // All args nullable:  anything goes!
      }
    }
  }

  /*
   * This next part consists of several sample classes that provide
   * demonstrations of conditions that cause NullPointerTester
   * to succeed/fail.
   */

  /** Lots of well-behaved methods. */
  @SuppressWarnings("unused") // used by reflection
  private static class PassObject extends SomeClassThatDoesNotUseNullable {

      QueuingRemovalListener<K, V> listener, K key, V value, RemovalCause cause) {
    RemovalNotification<K, V> notification = listener.remove();
    assertThat(notification.getKey()).isSameInstanceAs(key);
    assertThat(notification.getValue()).isSameInstanceAs(value);
    assertThat(notification.getCause()).isEqualTo(cause);
  }

  // Segment core tests

  public void testNewEntry() {

      QueuingRemovalListener<K, V> listener, K key, V value, RemovalCause cause) {
    RemovalNotification<K, V> notification = listener.remove();
    assertThat(notification.getKey()).isSameInstanceAs(key);
    assertThat(notification.getValue()).isSameInstanceAs(value);
    assertThat(notification.getCause()).isEqualTo(cause);
  }

  // Segment core tests

  public void testNewEntry() {