def compute(self, today, assets, out, *arrays):
        raise NotImplementedError()
if all partition columns are still present then keep partitioning,
dataset/ETHPy150Open quantopian/zipline/zipline/pipeline/mixins.py/CustomTermMixin.compute--crossover with--dataset/ETHPy150Open uwescience/raco/raco/algebra.py/Project.partitioning