How to get categorical values in catboost

Question

This is my data. I created a model with CatBoostClassifier().

I can get the feature names list with:

>>> model.feature_names_
['title', 'value']

First question: How can I get the title "predict"?

I can get the predict values in a list with:

>>> model.get_all_params()["class_names"]
['x', 'y', 'z']

Second question: How can I get the categorical values list? I need the title list of ['a', 'b', 'c'].

I have read the documentation but I couldn't see any solution.

Note: I won't have the original data, I will only have the model file.