shadows/framework/src/main/java/org/robolectric/shadows/ShadowMediaRouter.java
public void addBluetoothRoute() {
    updateBluetoothAudioRoute(BLUETOOTH_DEVICE_NAME);

    if (RuntimeEnvironment.getApiLevel() <= JELLY_BEAN_MR1) {
      ReflectionHelpers.callInstanceMethod(
          MediaRouter.class,
          realObject,
          "selectRouteInt",
          ClassParameter.from(int.class, MediaRouter.ROUTE_TYPE_LIVE_AUDIO),
          ClassParameter.from(RouteInfo.class, getBluetoothA2dpRoute()));
    } else {
      realObject.selectRoute(MediaRouter.ROUTE_TYPE_LIVE_AUDIO, getBluetoothA2dpRoute());
    }
  }
public void addBluetoothRoute() {
    updateBluetoothAudioRoute(BLUETOOTH_DEVICE_NAME);

    if (RuntimeEnvironment.getApiLevel() <= JELLY_BEAN_MR1) {
      ReflectionHelpers.callInstanceMethod(
          MediaRouter.class,
          realObject,
          "selectRouteInt",
          ClassParameter.from(int.class, MediaRouter.ROUTE_TYPE_LIVE_AUDIO),
          ClassParameter.from(RouteInfo.class, getBluetoothA2dpRoute()));
    } else {
      realObject.selectRoute(MediaRouter.ROUTE_TYPE_LIVE_AUDIO, getBluetoothA2dpRoute());
    }
  }
Adds the Bluetooth A2DP route and ensures it's the selected route, simulating connecting a
Bluetooth device.