Confusion in pretrained model.

Hello.

I am trying to run your model and I have some confusion in your pre-trained model.

It seems that ``train.py`` trained the model with doublehead model, but in the `interact.py`, the code loads `LMHeadmodel`.

Why are they using different models?

So in the pre-trained model, actually, next sentence classification is not implemented?

Compare the model setup in train.py with the model loading in interact.py, starting at the training and pretrained-model entry points. Trace whether the doublehead and LMHeadmodel paths are intentional, then document which model is shipped and whether next-sentence classification is included.

Written by the indexing model from the issue text.