Cannot run predictions in batches

Hi ,

I am trying now to predict for batch users, so I am using your suggestion from issue #240.
I am getting an error after first batch.
Do I understand correctly, that in liпhtfm.py on the row 814: `n_users = user_ids.max() + 1` , meaning that if I will send users_ids for the first batch, it will work, but starting from second not, because user_ids=[7,7,7,8,8,8] and features [1,2,3,1,2,3] will give n_users=9 and user_features.shape[0]=6 and throught an error "Number of user feature rows does not equal the number of users"
What am doing wrong?

_Originally posted by @maffka123 in https://github.com/lyst/lightfm/issues/240#issuecomment-878569973_

Start with lightfm.py around row 814 and review the batching discussion in issue #240. Reproduce the reported second-batch input with user_ids [7,7,7,8,8,8] and the corresponding features, then determine the expected behavior for batched prediction and document or test the resolved behavior.

Written by the indexing model from the issue text.