attribute sliced mode share summing to 1 for each attribute class

[elizabethc-arup]

For the NZ ABM, we are looking to build a regional benchmark to compare the mode shares within each region. This BM makes use of the destination_mode_shares_comparison BM with the groupby_person_attributes parameter to group the mode shares by region.

The output of the current implementation of the handler/ BM sums the mode shares for all classes to 1, however, for our particular instance, we would like to alter it so that the mode shares sum to 1 per region (class) to allow for the comparisons regionally.

From what I understand, there seems to be two ways to implement this case, with the first being to implement it as a separate NZ-specific BM in the benchmarking.py and the other to implement it as a more general case - perhaps involving a boolean parameter or a separate handler class to enable this option. I was wondering which would be the more suitable option of implementation in the best interest of Elara?