Grouped time series predictors were not being saved due to an error in SQL Alchemy, as it could not use frozensets as keys. These frozensets were used to store ICPs for each different group. This PR changes those keys to a simple '_'.join() of the values in the grouped columns for each possible group.
Why
Solves M#1186.
Grouped time series predictors were not being saved due to an error in SQL Alchemy, as it could not use
frozensetsas keys. Thesefrozensetswere used to store ICPs for each different group. This PR changes those keys to a simple'_'.join()of the values in the grouped columns for each possible group.Note: ignore deceiving branch name