“StorageMetadata”类型的值没有成员“downloadURL”

// MARK: - handleRegister
func handleRegister() {
    guard let email = emailTextField.text, let password = passwordTextField.text, let name = nameTextField.text else {
        print("Error")
        return
    }

    Auth.auth().createUser(withEmail: email, password: password) { (user, error) in
        if error != nil {
            // print("Error")
            return
        }

        // MARK: - hadleLogin// 

        guard let uid = Auth.auth().currentUser?.uid  else {
            return
        }

        // MARK: - image successful authenficated user

        let imageName = NSUUID().uuidString
        let storageRef = Storage.storage().reference().child("profile_images").child("\(imageName).png")

        if let profileImageUrl = self.profileImageView.image, let  uploadData = UIImageJPEGRepresentation(self.profileImageView.image!, 0.1) {
            storageRef.putData(uploadData, metadata: nil, completion: { (metadata, error) in

                if error != nil, metadata != nil {
                    print(error ?? "")
                    return

                }

                storageRef.downloadURL(completion: { (url, error) in
                    if error != nil {
                        print(error!.localizedDescription)
                        return
                    }
                    if let profileImageUrl = url?.absoluteString {
                        let values = ["name": name, "email": email, "profileImageUrl": profileImageUrl]
                        self.registeUserIntoDatabaseWithUID(uid: uid, values: values as [String : AnyObject])
                    }
                })
            })
        }
    }
}