import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import okhttp3.Credentials;
import okhttp3.OkHttpClient;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory; //marca el error


/**
 *
 * @author
 */
public class ConfigRetrofit {

    private static final String url = "mi url";

    private static final OkHttpClient.Builder httpClient = new OkHttpClient.Builder();


     private static Retrofit.Builder builder =
            new Retrofit.Builder()
                    .baseUrl(url)
                    .addConverterFactory(GsonConverterFactory.create())
                   ;