Ask about VQA model of x-lxmert

Thank you for your great contribution about x-lxmert. I want to build a VQA model based on the X-LXMERT architecture. But when I looked on [https://github.com/allenai/x-lxmert/blob/master/x-lxmert/src/tasks/vqa_model.py](https://github.com/allenai/x-lxmert/blob/master/x-lxmert/src/tasks/vqa_model.py), I could see you just used the LXMERT API called from Hugging Face. Beside that, on line 20, `self._init_weights(self.logit_fc)`, the attribute `self.logit_fc` wasn't even defined anyway. So i wonder is this part still using X-LXMERT architecture ?