Client.swift

class Client {
    var baseURL = "http://dev.whatever.com/"

    func execute(request : Request, completionHandler: (Response<AnyObject, NSError>) -> Void){
        Alamofire.request(request.method, baseURL + request.path, parameters: request.parameters())
            .responseJSON { response in
                completionHandler(response)
        }
    }
}

Client().execute(request: AuthRequest(/*Insert parameters here*/), completionHandler: { response in } )