if (set == null) {
        return ImmutableSet.of();
      }
      ImmutableSet<E> ret = ImmutableEnumSet.asImmutable(set);
      set = null; // subsequent manual manipulation of the accumulator mustn't affect ret
      return ret;
    }
  }

  @GwtIncompatible
  @SuppressWarnings({"rawtypes", "unchecked"})
  static <E extends Comparable<? super E>>

/**
 * Superclass for all {@code Multimap} testers.
 *
 * @author Louis Wasserman
 */
@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")
@NullMarked
public abstract class AbstractMultimapTester<

 *
 * @author Chris Povirk
 * @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")
@NullMarked
public class MapPutAllTester<K extends @Nullable Object, V extends @Nullable Object>

    interface EnumConsumer {
        void accept(RequestParam rp);
    }

    @Mock
    EnumConsumer consumer;

    @Test
    @DisplayName("Enum value can be passed to collaborators without side effects")
    void enumUsedWithCollaboratorHasNoSideEffects() {
        // Arrange: pick a value and a mocked consumer
        RequestParam rp = RequestParam.NO_RETRY;

        // Act: pass to the collaborator

 *
 * @author Chris Povirk
 * @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 MapCreationTester<K, V> extends AbstractMapTester<K, V> {
  @MapFeature.Require(ALLOWS_NULL_KEYS)

import org.junit.Ignore;

/** Tester for {@code BiMap.put} and {@code BiMap.forcePut}. */
@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 BiMapPutTester<K, V> extends AbstractBiMapTester<K, V> {

  @MapFeature.Require(SUPPORTS_PUT)

 *
 * @author George van den Driessche
 */
@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 CollectionRemoveTester<E> extends AbstractCollectionTester<E> {

/**
 * Tester for {@code Multimap.entries}.
 *
 * @author Louis Wasserman
 */
@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 MultimapEntriesTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {

/**
 * Tests for {@link Multimap#replaceValues(Object, Iterable)}.
 *
 * @author Louis Wasserman
 */
@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 MultimapReplaceValuesTester<K, V>
    extends AbstractMultimapTester<K, V, Multimap<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 ListAddAtIndexTester<E> extends AbstractListTester<E> {