TypeError: Can't instantiate abstract class CategoricalDissimilarity with abstract methods compile_d_mat, d

[sangwonme]

Hi. Thanks for sharing the awesome python package!
I'm so glad there's a great implementation for gamma metric!

However, I need help with running the code.
I met error while running cat_dissim = CategoricalDissimilarity(continuum.categories, delta_empty=1), the code from tutorial here, the last cell.

cat_dissim = CategoricalDissimilarity(continuum.categories, delta_empty=1) TypeError: Can't instantiate abstract class CategoricalDissimilarity with abstract methods compile_d_mat, d

To be sure, I downloaded the same data (AlexPaulSuzan.csv) and installed/imported all modules that are needed.
Could you please explain what the error states for?