How to calculate shapley values for HSTreeClassifier

[victor-ML]

In figure 6 from the paper SHAP summary plots are created for HSTreeClassifier and compared against those from sklearn's RandomForestClassifier. That's exactly what I want to do. However when I plug it to the TreeExplainer I get:

InvalidModelError: Model type not yet supported by TreeExplainer: <class 'imodels.tree.hierarchical_shrinkage.HSTreeClassifier'>

I did my best to search in the repo for some kindof shap wrapper and found nothing. Help? Thanks!