@abstractmethod
    def _change_colours(self, colour, attr, bg):
Return the offspring of partially matched crossover on the candidates.
dataset/ETHPy150Open peterbrittain/asciimatics/asciimatics/screen.py/Screen._change_colours--crossover with--dataset/ETHPy150Open aarongarrett/inspyred/inspyred/ec/variators/crossovers.py/partially_matched_crossover