BiMap<Integer, String> inverse = bimap.inverse();
    assertSame(bimap, inverse.inverse());
    assertTrue(inverse instanceof SynchronizedBiMap);
    assertSame(mutex, ((SynchronizedBiMap<?, ?>) inverse).mutex);
  }

  @Override
  public void testValues() {
    BiMap<String, Integer> map = create();
    Set<Integer> values = map.values();
    assertTrue(values instanceof SynchronizedSet);

import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;
import org.junit.Ignore;

/** Tester for {@code BiMap.put} and {@code BiMap.forcePut}. */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class BiMapPutTester<K, V> extends AbstractBiMapTester<K, V> {

      extends AbstractSet<T> {
    final HashBiMap<K, V> biMap;

    View(HashBiMap<K, V> biMap) {
      this.biMap = biMap;
    }

    @ParametricNullness
    abstract T forEntry(int entry);

    @Override
    public Iterator<T> iterator() {
      return new Iterator<T>() {
        private int index = biMap.firstInInsertionOrder;
        private int indexToRemove = ABSENT;

  public void testCreate() {
    EnumHashBiMap<Currency, String> bimap = EnumHashBiMap.create(Currency.class);
    assertTrue(bimap.isEmpty());
    assertEquals("{}", bimap.toString());
    assertEquals(HashBiMap.create(), bimap);
    bimap.put(Currency.DOLLAR, "dollar");
    assertEquals("dollar", bimap.get(Currency.DOLLAR));
    assertEquals(Currency.DOLLAR, bimap.inverse().get("dollar"));
  }

  public void testCreateFromMap() {

  }

  @LazyInit @RetainedWith @CheckForNull private transient BiMap<V, K> inverse;

  @Override
  public BiMap<V, K> inverse() {
    BiMap<V, K> result = inverse;
    return (result == null) ? inverse = new Inverse() : result;
  }

  private final class Inverse extends IteratorBasedAbstractMap<V, K>
      implements BiMap<V, K>, Serializable {
    BiMap<K, V> forward() {
      return HashBiMap.this;
    }

      ImmutableBiMap<K, V> bimap = (ImmutableBiMap<K, V>) map;
      // TODO(lowasser): if we need to make a copy of a BiMap because the
      // forward map is a view, don't make a copy of the non-view delegate map
      if (!bimap.isPartialView()) {
        return bimap;
      }
    }
    return copyOf(map.entrySet());
  }

  /**

/**
 * Creates, based on your criteria, a JUnit test suite that exhaustively tests a {@code BiMap}
 * implementation.
 *
 * @author Louis Wasserman
 */
@GwtIncompatible
public class BiMapTestSuiteBuilder<K, V>
    extends PerCollectionSizeTestSuiteBuilder<
        BiMapTestSuiteBuilder<K, V>, TestBiMapGenerator<K, V>, BiMap<K, V>, Entry<K, V>> {

/**
 * A {@code BiMap} backed by an {@code EnumMap} instance for keys-to-values, and a {@code HashMap}
 * instance for values-to-keys. Null keys are not permitted, but null values are. An {@code
 * EnumHashBiMap} and its inverse are both serializable.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#bimap">{@code BiMap}</a>.
 *
 * @author Mike Bostock

  @Override
  public Set<N> predecessors() {
    return Collections.unmodifiableSet(((BiMap<E, N>) inEdgeMap).values());
  }

  @Override
  public Set<N> successors() {
    return Collections.unmodifiableSet(((BiMap<E, N>) outEdgeMap).values());
  }

  @Override
  public Set<E> edgesConnecting(N node) {
    return new EdgesConnecting<>(((BiMap<E, N>) outEdgeMap).inverse(), node);
  }

import java.util.Collections;
import java.util.List;
import org.junit.Ignore;

/**
 * Tests for the {@code inverse} view of a BiMap.
 *
 * <p>This assumes that {@code bimap.inverse().inverse() == bimap}, which is not technically
 * required but is fulfilled by all current implementations.
 *
 * @author Louis Wasserman
 */
@GwtCompatible(emulated = true)