Dagger 2 Code Cheat Sheet (from https://guides.codepath.com/android/Dependency-Injection-with-Dagger-2)

SampleAppComponent.class

@PerApp
@Component(
    modules = {
        SampleAppModule.class,
        DataModule.class,
        NetworkModule.class
    }
    dependencies = {
        OtherComponent.class
    }
)
public interface SampleAppComponent {
  public void inject(SomeActivity someActivity);

  public void inject(SomeFragment someFragment);

  public void inject(SomeOtherFragment someOtherFragment);

  Application application();

  Picasso picasso();

  Gson gson();

  OkHttpClient okHttpClient();
}

SampleAppModule.class

@Module
public class SampleAppModule {

  static final String PREFS_DEFAULT = "myapp";

  final SampleApp app;

  public AppModule(SampleApp app) {
    this.app = app;
  }

  @Provides @PerApp SampleApp provideSampleApp() {
    return app;
  }

  @Provides @PerApp Application provideApplication(SampleApp app) {
    return app;
  }

  @Provides @PerApp SharedPreferences provideSharedPrefs(Application app) {
    return app.getSharedPreferences(PREFS_DEFAULT, Context.MODE_PRIVATE);
  }

  @Provides @PerApp Gson provideGson() {
    return new Gson();
  }
}