Same utility, different weighting

[mdbenito]

As suggested by a reviewer

It seems like the class-specific aspects of CS are orthogonal to their choice
to use Shapley values, and we could just as easily define a class-specific
version of Data Banzhaf (say ‘‘CDB"). Comparing CS to DB is a bit
unsatisfactory, because we don't know if the performance differences are due
to the class specificity or the Shapley/Banzhaf choice, and this would be best
resolved by including the new CDB method.