code: public boolean getTorchMode(@NonNull String cameraId) {
      Preconditions.checkNotNull(cameraId);
      Preconditions.checkArgument(cameraIdToCharacteristics.keySet().contains(cameraId));
      Boolean torchState = cameraTorches.get(cameraId);
      return torchState;
    }
docs: Returns what the supplied camera's torch is set to.