}

  private static <N, V> GraphConnections<N, V> connectionsOf(ValueGraph<N, V> graph, N node) {
    Function<N, V> successorNodeToValueFn =
        (N successorNode) ->
            // requireNonNull is safe because the endpoint pair comes from the graph.
            requireNonNull(graph.edgeValueOrDefault(node, successorNode, null));
    return graph.isDirected()
        ? DirectedGraphConnections.ofImmutable(

for whichever features you need:

```
OkHttpDebugLogging.enableHttp2()
OkHttpDebugLogging.enableTaskRunner()
```

### Activating on Android

```
$ adb shell setprop log.tag.okhttp.Http2 DEBUG
$ adb shell setprop log.tag.okhttp.TaskRunner DEBUG
$ adb logcat '*:E' 'okhttp.Http2:D' 'okhttp.TaskRunner:D'
```

### HTTP/2 Frame Logging

 *
 * @author Jared Levy
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class QueueElementTester<E> extends AbstractQueueTester<E> {
  @CollectionSize.Require(ZERO)

 *
 * @author Jared Levy
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class QueuePeekTester<E> extends AbstractQueueTester<E> {
  @CollectionSize.Require(ZERO)

 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class SetAddAllTester<E> extends AbstractSetTester<E> {
  @CollectionFeature.Require(SUPPORTS_ADD)

    }
    closeMethod.invoke(wrapper);
    assertThat(delegate.isTerminated()).isTrue();
  }

  private static boolean isAndroid() {
    return System.getProperty("java.runtime.name", "").contains("Android");
  }

  private static boolean isBeforeJava19() {
    return JAVA_SPECIFICATION_VERSION.value().equals("1.8")
        || parseInt(JAVA_SPECIFICATION_VERSION.value()) < 19;
  }

 * @param <V> The value type of the tested multimap.
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class SortedSetMultimapAsMapTester<K, V>
    extends AbstractMultimapTester<K, V, SortedSetMultimap<K, V>> {

 *
 * @author Chris Povirk
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class ListAddAllTester<E> extends AbstractListTester<E> {
  @CollectionFeature.Require(SUPPORTS_ADD)

  /**
   * Returns the equivalent {@code com.google.common.base.Optional} value to the given {@code
   * java.util.Optional}, or {@code null} if the argument is null.
   *
   * @since 21.0 (but only since 33.4.0 in the Android flavor)
   */
  @SuppressWarnings("NullableOptional") // Null passthrough is reasonable for type conversions
  public static <T> @Nullable Optional<T> fromJavaUtil(
      java.util.@Nullable Optional<T> javaUtilOptional) {

    assertThat(letters).containsExactly("a", "b", "c").inOrder();
  }

  @J2ktIncompatible // Kotlin Native's regex is based on Apache Harmony, like old Android
  @GwtIncompatible // java.util.regex.Pattern
  @AndroidIncompatible // Bug in older versions of Android we test against, since fixed.
  public void testPatternSplitLookBehind() {
    if (!CommonPattern.isPcreLike()) {
      return;
    }