Map<K, ? extends V> map) {
    if (map instanceof SortedMap) {
      return Collections.unmodifiableSortedMap((SortedMap<K, ? extends V>) map);
    } else {
      return Collections.unmodifiableMap(map);
    }
  }

  private static class MapDifferenceImpl<K extends @Nullable Object, V extends @Nullable Object>

   * list is threadsafe if the supplied list and function are.
   *
   * <p>If only a {@code Collection} or {@code Iterable} input is available, use {@link
   * Collections2#transform} or {@link Iterables#transform}.
   *
   * <p><b>Note:</b> serializing the returned list is implemented by serializing {@code fromList},

 * elements.
 *
 * <p>The collections created by {@link #createCollection()} may or may not allow duplicates. If the
 * collection, such as a {@link Set}, does not support duplicates, an added key-value pair will
 * replace an existing pair with the same key and value, if such a pair is present. With collections
 * like {@link List} that allow duplicates, the collection will keep the existing key-value pairs

 * elements.
 *
 * <p>The collections created by {@link #createCollection()} may or may not allow duplicates. If the
 * collection, such as a {@link Set}, does not support duplicates, an added key-value pair will
 * replace an existing pair with the same key and value, if such a pair is present. With collections
 * like {@link List} that allow duplicates, the collection will keep the existing key-value pairs

        return Collections.unmodifiableSortedSet((SortedSet<E>) collection);
      } else if (collection instanceof Set) {
        return Collections.unmodifiableSet((Set<E>) collection);
      } else if (collection instanceof List) {
        return Collections.unmodifiableList((List<E>) collection);
      } else {
        return Collections.unmodifiableCollection(collection);
      }
    }

        return Collections.unmodifiableSortedSet((SortedSet<E>) collection);
      } else if (collection instanceof Set) {
        return Collections.unmodifiableSet((Set<E>) collection);
      } else if (collection instanceof List) {
        return Collections.unmodifiableList((List<E>) collection);
      } else {
        return Collections.unmodifiableCollection(collection);
      }
    }

          };
        }
      };
    }

    // See Collections.CheckedMap.CheckedEntrySet for details on attacks.

    @Override
    public @Nullable Object[] toArray() {
      synchronized (mutex) {
        /*
         * toArrayImpl returns `@Nullable Object[]` rather than `Object[]` but only because it can
         * be used with collections that may contain null. This collection never contains nulls, so

          };
        }
      };
    }

    // See Collections.CheckedMap.CheckedEntrySet for details on attacks.

    @Override
    public @Nullable Object[] toArray() {
      synchronized (mutex) {
        /*
         * toArrayImpl returns `@Nullable Object[]` rather than `Object[]` but only because it can
         * be used with collections that may contain null. This collection never contains nulls, so

   * @throws IllegalArgumentException if {@code map} is not empty
   * @deprecated Use {@link Collections#newSetFromMap} instead.
   */
  @InlineMe(replacement = "Collections.newSetFromMap(map)", imports = "java.util.Collections")
  @Deprecated
  public static <E extends @Nullable Object> Set<E> newSetFromMap(
      Map<E, Boolean> map) {
    return Collections.newSetFromMap(map);
  }

  /**

   * @throws IllegalArgumentException if {@code map} is not empty
   * @deprecated Use {@link Collections#newSetFromMap} instead.
   */
  @InlineMe(replacement = "Collections.newSetFromMap(map)", imports = "java.util.Collections")
  @Deprecated
  public static <E extends @Nullable Object> Set<E> newSetFromMap(
      Map<E, Boolean> map) {
    return Collections.newSetFromMap(map);
  }

  /**