Reflection - getting private field value

I am testing viewmodel and would like to access private field:

    val currentTrainingField = viewModel.javaClass.getDeclaredField("currentTraining")
    currentTrainingField.isAccessible = true
    val currentTraining = currentTrainingField.get(currentSetField)

I receive an error: Can not set com.myapp.Training field com.myapp.WorkoutExerciseViewModel.currentTraining to java.lang.reflect.Field

How should I handle that?