struct RestfulApi {

    public static let sessionManager: SessionManager = {
        var defaultHeaders = SessionManager.defaultHTTPHeaders
        defaultHeaders["app-version"] = "1.0"
        defaultHeaders["DNT"] = "1 (Do Not TrackEnabled)"

        let configuration = URLSessionConfiguration.default
        configuration.httpAdditionalHeaders = defaultHeaders

        return SessionManager(configuration: configuration)
    }()

    public func doLogin(username: String, password:String, deviceID: String) {
        let parameters: Parameters = ["email": username,
                                      "password": password,
                                      "deviceID": deviceID]
        RestfulApi.sessionManager.request(ServerConstants.getRestfulActionURL(action: .login), method: .post, parameters: parameters, encoding: JSONEncoding.default)
            .response {
                response in
                log.verbose(response)
            }
    }
}

DefaultDataResponse(request: Optional(https://example.com/signin), response: Optional(<NSHTTPURLResponse: 0x60000022ff60> { URL: