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

AndroidViewModelFactory.java

@NonNull
@Override
public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
    if (AndroidViewModel.class.isAssignableFrom(modelClass)) {
        try {
            return modelClass.getConstructor(Application.class).newInstance(mApplication);
        } catch ... {
            ...
        }
    }
    return super.create(modelClass);
}