}
    };
  }

  /** The implementation of {@link Multimaps#unmodifiableEntries}. */
  static class UnmodifiableEntries<K extends @Nullable Object, V extends @Nullable Object>
      extends ForwardingCollection<Entry<K, V>> {
    private final Collection<Entry<K, V>> entries;

    UnmodifiableEntries(Collection<Entry<K, V>> entries) {
      this.entries = entries;
    }

    @Override