override fun requestHeadersEnd(
          call: Call,
          request: Request,
        ) = TODO()

        override fun requestBodyStart(call: Call) = TODO()

        override fun requestBodyEnd(
          call: Call,
          byteCount: Long,
        ) = TODO()

        override fun requestFailed(
          call: Call,
          ioe: IOException,

          return ImmutableSet.of().iterator();
        }
      };

  /** Queue that discards all elements. */
  @SuppressWarnings("unchecked") // impl never uses a parameter or returns any non-null value
  static <E> Queue<E> discardingQueue() {
    return (Queue) DISCARDING_QUEUE;
  }

  /*
   * Note: All of this duplicate code sucks, but it saves a lot of memory. If only Java had mixins!

import java.util.Collection;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * When describing the features of the collection produced by a given generator (i.e. in a call to
 * {@link
 * com.google.common.collect.testing.FeatureSpecificTestSuiteBuilder#withFeatures(Feature...)}),
 * this annotation specifies each of the different sizes for which a test suite should be built. (In

import java.util.Collection;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * When describing the features of the collection produced by a given generator (i.e. in a call to
 * {@link
 * com.google.common.collect.testing.FeatureSpecificTestSuiteBuilder#withFeatures(Feature...)}),
 * this annotation specifies each of the different sizes for which a test suite should be built. (In

	Spectre    = flag.String("spectre", "", "enable spectre mitigations in `list` (all, ret)")
	Std        = flag.Bool("std", false, "building standard library")
)

var DebugFlags struct {
	CompressInstructions int    `help:"use compressed instructions when possible (if supported by architecture)"`
	MayMoreStack         string `help:"call named function before all stack growth checks"`

        when(mockHit.getIndex()).thenReturn("test-index");
        when(mockHit.getId()).thenReturn("doc1");

        // Setup scroll response (empty on second call)
        when(mockClient.prepareSearchScroll("scroll1")).thenReturn(mockScrollBuilder);
        when(mockScrollBuilder.setScroll(any(Scroll.class))).thenReturn(mockScrollBuilder);

 *       objects into a non-recursive form, you can use {@code forGraph()}.
 * </ul>
 *
 * @author Jens Nyman
 * @param <N> Node parameter type
 * @since 23.1
 */
@DoNotMock(
    "Call forGraph or forTree, passing a lambda or a Graph with the desired edges (built with"
        + " GraphBuilder)")
public abstract class Traverser<N> {
  private final SuccessorsFunction<N> successorFunction;

      .tag(Integer.class, 5)
      .tag(String.class, "hello")
      .build();
    Call call = client.newCall(request);

    assertEquals(5, call.tag(Integer.class));
    assertEquals("hello", call.tag(String.class));
    assertEquals(null, call.tag(Boolean.class));
    assertEquals(null, call.tag(Object.class));
  }

  @Test
  public void tagsCanBeComputed() {
    Request request = new Request.Builder()

        .build();

    final long startNanos = System.nanoTime();
    final Call call = client.newCall(request);

    // Schedule a job to cancel the call in 1 second.
    executor.schedule(() -> {
      System.out.printf("%.2f Canceling call.%n", (System.nanoTime() - startNanos) / 1e9f);
      call.cancel();
      System.out.printf("%.2f Canceled call.%n", (System.nanoTime() - startNanos) / 1e9f);
    }, 1, TimeUnit.SECONDS);

) : EventSource,
  ServerSentEventReader.Callback,
  Callback {
  private var call: Call? = null

  @Volatile private var canceled = false

  fun connect(callFactory: Call.Factory) {
    call =
      callFactory.newCall(request).apply {
        enqueue(this@RealEventSource)
      }
  }

  override fun onResponse(
    call: Call,
    response: Response,
  ) {
    processResponse(response)
  }