* object being tested for equality to the custom interface. {@code ForwardingObject} implements no
 * such custom interfaces directly; they are implemented only in subclasses. Therefore, forwarding
 * {@code equals} would break symmetry, as the forwarding object might consider itself equal to the
 * object being tested, but the reverse could not be true. This behavior is consistent with the

    assertTrue(iterator.hasNext());
    assertEquals("a", iterator.next());
    assertThrows(UnsupportedOperationException.class, () -> iterator.remove());
  }

  @SuppressWarnings("DoNotCall")
  public void testAdd() {
    ListIterator<String> iterator = create();

    assertTrue(iterator.hasNext());
    assertEquals("a", iterator.next());
    assertEquals("b", iterator.next());
    assertEquals("b", iterator.previous());

import com.google.common.annotations.GwtCompatible;
import java.util.Queue;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Creates queues, containing sample elements, to be tested.
 *
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public interface TestQueueGenerator<E extends @Nullable Object> extends TestCollectionGenerator<E> {
  @Override
  Queue<E> create(Object... elements);

| Android default  | ✅      | Android 10+  | [BoringSSL]     |                                                              |
| [GraalVM]        | ✅      |              | [OpenJDK]       | Only actively tested with JDK 11, not with 8 target          |
| [Bouncy Castle]  | ✅      |              | [Bouncy Castle] | [Tracking bug.][bug5698]                                     |

import com.google.common.annotations.GwtCompatible;
import java.util.List;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Creates sets, containing sample elements, to be tested.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullMarked
public interface TestListGenerator<E extends @Nullable Object> extends TestCollectionGenerator<E> {
  @Override
  List<E> create(Object... elements);

import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Testers for {@link SetMultimap#asMap}.
 *
 * @author Louis Wasserman
 * @param <K> The key type of the tested multimap.
 * @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")

import java.util.Map.Entry;
import java.util.SortedMap;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Creates sorted maps, containing sample elements, to be tested.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@NullMarked
public interface TestSortedMapGenerator<K extends @Nullable Object, V extends @Nullable Object>
    extends TestMapGenerator<K, V> {
  @Override

import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link Files}.
 *
 * <p>Some methods are tested in separate files:
 *
 * <ul>
 *   <li>{@link Files#fileTraverser()} is tested in {@link FilesFileTraverserTest}.
 *   <li>{@link Files#createTempDir()} is tested in {@link FilesCreateTempDirTest}.
 * </ul>
 *
 * @author Chris Nokleberg
 */

      "Reusing an existing edge to connect different nodes succeeded";

  /** Creates and returns an instance of the graph to be tested. */
  abstract Network<Integer, String> createGraph();

  /**
   * A proxy method that adds the node {@code n} to the graph being tested. In case of Immutable
   * graph implementations, this method should replace {@link #network} with a new graph that
   * includes this node.
   */

 *
 * <p>TODO: see how much of this is actually needed once Map testers are written. (It was cloned
 * from AbstractCollectionTester.)
 *
 * @param <K> the key type of the map to be tested.
 * @param <V> the value type of the map to be tested.
 * @author George van den Driessche
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")