How the base ViewModelFactory works for https://medium.com/@josep.rodriguez/internals-of-android-architecture-components-part-i-the-viewmodel-d893e362a0d9

GenericViewModelFactory.java

public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
    try {
        return modelClass.newInstance();
    } catch (InstantiationException e) {
        ...
    }
}