Map<? extends K, ? extends V> map, Comparator<? super K> comparator) {
    boolean sameComparator = false;
    if (map instanceof SortedMap) {
      SortedMap<?, ?> sortedMap = (SortedMap<?, ?>) map;
      Comparator<?> comparator2 = sortedMap.comparator();
      sameComparator =
          (comparator2 == null) ? comparator == NATURAL_ORDER : comparator.equals(comparator2);
    }

      SortedMap<K, V> sortedMap, @CheckForNull Object mutex) {
    return new SynchronizedSortedMap<>(sortedMap, mutex);
  }

  static class SynchronizedSortedMap<K extends @Nullable Object, V extends @Nullable Object>
      extends SynchronizedMap<K, V> implements SortedMap<K, V> {

    SynchronizedSortedMap(SortedMap<K, V> delegate, @CheckForNull Object mutex) {

      SortedMap<K, V> sortedMap, @CheckForNull Object mutex) {
    return new SynchronizedSortedMap<>(sortedMap, mutex);
  }

  static class SynchronizedSortedMap<K extends @Nullable Object, V extends @Nullable Object>
      extends SynchronizedMap<K, V> implements SortedMap<K, V> {

    SynchronizedSortedMap(SortedMap<K, V> delegate, @CheckForNull Object mutex) {

      Map<? extends K, ? extends V> map, Comparator<? super K> comparator) {
    boolean sameComparator = false;
    if (map instanceof SortedMap) {
      SortedMap<?, ?> sortedMap = (SortedMap<?, ?>) map;
      Comparator<?> comparator2 = sortedMap.comparator();
      sameComparator =
          (comparator2 == null) ? comparator == NATURAL_ORDER : comparator.equals(comparator2);
    }