带有翻新和匕首的MockWebServer

我试图为我的android项目实施检测测试。在我的主要项目中，我使用了匕首和翻新版，并通过我的模块提供了翻新版。

这是我提供改造的模块：

@Module
public class NetModule {

    @Provides
    @Singleton
    OkHttpClient.Builder provideOkHttpClientBuilder(){
        OkHttpClient.Builder okHttp = new OkHttpClient.Builder();

        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        NoCacheInterceptor noCacheInterceptor = new NoCacheInterceptor();
        interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);

        if (!okHttp.interceptors().contains(interceptor))
            okHttp.addInterceptor(interceptor);

        if (!okHttp.interceptors().contains(noCacheInterceptor))
            okHttp.addInterceptor(noCacheInterceptor);

        return okHttp;
    }

    @Provides
    Retrofit provideRetrofit(OkHttpClient.Builder httpClient){
        return new Retrofit.Builder()
              .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
              .addConverterFactory(GsonConverterFactory.create())
              .baseUrl(Constant.BASE_URL)
              .client(httpClient.build()).build();
    }

}

然后，在我的androidTest文件夹中，我创建了TestModule来提供MockWebServer的改造，如下所示：

@Module
public class TestNetModule {
    private final MockWebServer mockWebServer;
    public TestNetModule() {
        mockWebServer = new MockWebServer();
    }

    @Provides
    @Singleton
    MockWebServer providerMockWebServer() {
        return new MockWebServer();
    }

    @Provides
    @Singleton
    OkHttpClient.Builder provideOkHttpClientBuilder(){
        OkHttpClient.Builder okHttp = new OkHttpClient.Builder();

        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        NoCacheInterceptor noCacheInterceptor = new NoCacheInterceptor();
        interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);

        if (!okHttp.interceptors().contains(interceptor))
            okHttp.addInterceptor(interceptor);

        if (!okHttp.interceptors().contains(noCacheInterceptor))
            okHttp.addInterceptor(noCacheInterceptor);

        return okHttp;
    }

    @Provides
    Retrofit.Builder provideRetrofitBuilder(OkHttpClient.Builder httpClient, MockWebServer mockWebServer){
        return new Retrofit.Builder()
              .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
              .addConverterFactory(GsonConverterFactory.create())
              .baseUrl(mockWebServer.url("/").toString())
              .client(httpClient.build()).build();
    }
}

运行测试时，我总是android.os.NetworkOnMainThreadException在code处出错.baseUrl(mockWebServer.url("/").toString())。如何正确实施带有调试和匕首的MockWebServer进行测试？