* equal.
   */
  boolean areEqual();

  /**
   * Returns an unmodifiable map containing the entries from the left map whose keys are not present
   * in the right map.
   */
  Map<K, V> entriesOnlyOnLeft();

  /**
   * Returns an unmodifiable map containing the entries from the right map whose keys are not
   * present in the left map.
   */
  Map<K, V> entriesOnlyOnRight();

  /**

   * equal.
   */
  boolean areEqual();

  /**
   * Returns an unmodifiable map containing the entries from the left map whose keys are not present
   * in the right map.
   */
  Map<K, V> entriesOnlyOnLeft();

  /**
   * Returns an unmodifiable map containing the entries from the right map whose keys are not
   * present in the left map.
   */
  Map<K, V> entriesOnlyOnRight();

  /**

 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface SortedMapDifference<K extends @Nullable Object, V extends @Nullable Object>
    extends MapDifference<K, V> {

  @Override
  SortedMap<K, V> entriesOnlyOnLeft();

  @Override
  SortedMap<K, V> entriesOnlyOnRight();

  @Override
  SortedMap<K, V> entriesInCommon();

  @Override
  SortedMap<K, ValueDifference<V>> entriesDiffering();

      if (object == this) {
        return true;
      }
      if (object instanceof MapDifference) {
        MapDifference<?, ?> other = (MapDifference<?, ?>) object;
        return entriesOnlyOnLeft().equals(other.entriesOnlyOnLeft())
            && entriesOnlyOnRight().equals(other.entriesOnlyOnRight())
            && entriesInCommon().equals(other.entriesInCommon())
            && entriesDiffering().equals(other.entriesDiffering());

      if (object == this) {
        return true;
      }
      if (object instanceof MapDifference) {
        MapDifference<?, ?> other = (MapDifference<?, ?>) object;
        return entriesOnlyOnLeft().equals(other.entriesOnlyOnLeft())
            && entriesOnlyOnRight().equals(other.entriesOnlyOnRight())
            && entriesInCommon().equals(other.entriesInCommon())
            && entriesDiffering().equals(other.entriesDiffering());