error when implement ATLConversationViewControllerDataSource

[KhaledAld]

this is my code :

class test: ATLConversationViewController, ATLConversationViewControllerDataSource, ATLConversationViewControllerDelegate {
    var dateFormatter: NSDateFormatter = NSDateFormatter()
    var usersArray: NSArray!

    override func viewDidLoad() {
        super.viewDidLoad()
        self.dataSource = self
        self.delegate = self
        print("addressBarController: \(self.addressBarController)")
        self.addressBarController.delegate = self

        // Uncomment the following line if you want to show avatars in 1:1 conversations
        // self.shouldDisplayAvatarItemForOneOtherParticipant = true

        // Setup the dateformatter used by the dataSource.
        self.dateFormatter.dateStyle = NSDateFormatterStyle.ShortStyle
        self.dateFormatter.timeStyle = NSDateFormatterStyle.ShortStyle

        self.configureUI()
    }

    // MARK - UI Configuration methods

    func configureUI() {
        ATLOutgoingMessageCollectionViewCell.appearance().messageTextColor = UIColor.whiteColor()
    }

    // MARK - ATLConversationViewControllerDelegate methods

    func conversationViewController(viewController: ATLConversationViewController, didSendMessage message: LYRMessage) {
        print("Message sent!")
    }

    func conversationViewController(viewController: ATLConversationViewController, didFailSendingMessage message: LYRMessage, error: NSError?) {
        print("Message failed to sent with error: \(error)")
    }

    func conversationViewController(viewController: ATLConversationViewController, didSelectMessage message: LYRMessage) {
        print("Message selected")
    }

    // MARK - ATLConversationViewControllerDataSource methods

    func conversationViewController(conversationViewController: ATLConversationViewController, participantForIdentifier participantIdentifier: String) -> ATLParticipant? {
        let user = PFUser()
        return user
    }

    func conversationViewController(conversationViewController: ATLConversationViewController, attributedStringForDisplayOfDate date: NSDate) -> NSAttributedString {
        return NSAttributedString()
    }

    func conversationViewController(conversationViewController: ATLConversationViewController, attributedStringForDisplayOfRecipientStatus recipientStatus: [NSObject:AnyObject]) -> NSAttributedString {
        return NSAttributedString()
    }

}

and this is error : Type 'test' does not conform to protocol 'ATLConversationViewControllerDataSource'