examples/research_projects/visual_bert/modeling_frcnn.py/ROIOutputs/_predict_objs
class ROIOutputs:    def _predict_objs(self, obj_logits, preds_per_image):
        probs = nn.functional.softmax(obj_logits, dim=-1)
        probs = probs.split(preds_per_image, dim=0)
        return probs