// Java 21 Sequenced Collections support
SequencedCollection<String> sequenced = CollectionsUtil.newLinkedHashSet();
String first = CollectionsUtil.getFirst(sequenced);
String last = CollectionsUtil.getLast(sequenced);
SequencedCollection<String> reversed = CollectionsUtil.reversed(sequenced);

// Specialized collections

    return Types.newParameterizedTypeWithOwner(
        resolvedOwner, (Class<?>) resolvedRawType, resolvedArgs);
  }

  private static <T> T expectArgument(Class<T> type, Object arg) {
    try {
      return type.cast(arg);
    } catch (ClassCastException e) {
      throw new IllegalArgumentException(arg + " is not a " + type.getSimpleName());
    }
  }

  /** A TypeTable maintains mapping from {@link TypeVariable} to types. */

    return Types.newParameterizedTypeWithOwner(
        resolvedOwner, (Class<?>) resolvedRawType, resolvedArgs);
  }

  private static <T> T expectArgument(Class<T> type, Object arg) {
    try {
      return type.cast(arg);
    } catch (ClassCastException e) {
      throw new IllegalArgumentException(arg + " is not a " + type.getSimpleName());
    }
  }

  /** A TypeTable maintains mapping from {@link TypeVariable} to types. */