Combinatorial Complex Attention Tutorial fails

[max-kat]

I tried to run your tutorial example for the combinatorial complex: https://pyt-team.github.io/topomodelx/notebooks/combinatorial/hmc_train.html
However I run into a problem when trying to actually train the model as I get the error:

RuntimeError: Batches of sparse tensors are not currently supported by the default collate_fn; please provide a custom collate_fn to handle them appropriately.

Do you have a fix for this problem or do I need to use dense tensors? or is there a better workaround?

Thanks for your help!