Can't call a non-function value of type "NSHTTPURLResponse"?

Question

I have seen this problem several times on this site, but none of the solutions seem to work.

I am expanding the alamofire request to have an array of repo objects as a result; however, I continue to get an error in the title. Here is the code:

 extension Alamofire.Request {
   class func repoArrayResponseSerializer() -> ResponseSerializer<Array<Repo>, NSError> {
    return ResponseSerializer { request, response, data, error in
        guard error == nil else { return .Failure(error!) }

        guard data != nil else { return .Failure(error!) }

        do {
            let jsonData: AnyObject? = try NSJSONSerialization.JSONObjectWithData(data!, options: .AllowFragments)
            let json = JSON(jsonData!)

            if json.error != nil || json == nil {
                return .Failure(error!)
            }

            var repos: Array = Array<Repo>()
            for (_, jsonRepo) in json {
                let repo = Repo(json: jsonRepo)
                repos.append(repo)
            }

            return .Success(repos)
        } catch {
            return .Failure(error as NSError)
        }
    }
}

func responseRepoArray(completionHandler: Result<Array<Repo>, NSError> -> Void) -> Self {
    return response(responseSerializer: Request.repoArrayResponseSerializer(), completionHandler: completionHandler)
}

}

Any help is appreciated.