multimap().clear();
    }
  }

  /** A skeleton implementation of {@link Multimap#asMap()}. */
  static final class AsMap<K extends @Nullable Object, V extends @Nullable Object>
      extends Maps.ViewCachingAbstractMap<K, Collection<V>> {
    @Weak private final Multimap<K, V> multimap;

    AsMap(Multimap<K, V> multimap) {
      this.multimap = checkNotNull(multimap);
    }

    @Override