gistfile1.txt

OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
httpClient.addNetworkInterceptor(new AddHeaderInterceptor(activity, action, version));

Retrofit retrofit = new Retrofit.Builder()
        .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
        .addConverterFactory(GsonConverterFactory.create())
        .baseUrl(ServiceFretebras.SERVICE_ENDPOINT)
        .build();
        
Class test

ServiceRequestConfig service = new ServiceRequestConfig(
                context, arg01, arg02);

        Observable<FreteDetalhes> observable = service
                .get()
                .........