 
   /// Returns a new string made by appending to the `String` an
   /// extension separator followed by a given extension.
+  @available(*, unavailable, message="Use stringByAppendingPathExtension on NSString instead.")
   public func stringByAppendingPathExtension(ext: String) -> String? {
     // FIXME: This method can return nil in practice, for example when self is
     // an empty string.  OTOH, this is not documented, documentatios says that

  // - (NSString *)stringByAppendingPathComponent:(NSString *)aString

  /// Returns a new string made by appending to the `String` a given string.
  public func stringByAppendingPathComponent(aString: String) -> String {
    return _ns.stringByAppendingPathComponent(aString)
  }


  /// Interprets the `String` as a path and returns the
  /// `String`’s extension, if any.
  @available(*, unavailable, message="Use pathExtension on NSString instead.")
  public var pathExtension: String {
    return _ns.pathExtension
  }
