Fix XLNet batch generation bug
When doing batch generation with XLNet, only the first element in the batch contains any predictions. This seems to be caused by the target_mapping being improperly initialized in prepare_inputs_for_generation.
Hi @neonbjb,

sorry to answer waaaay to late.
Batch generation currently does not work. See #3021

We are not sure yet when and how to add this feature.<|||||>Uhhhh.. but it could with this PR? I have it working on my cloned repo and used it in this writeup. Your call though.
https://nonint.com/2020/03/27/fine-tuning-xlnet-for-generation-tasks/