def __and__(self, other):
        if not isinstance(other, ConditionalFreqDist):
            return NotImplemented
        result = ConditionalFreqDist()
        for cond in self.conditions():
            newfreqdist = self[cond] & other[cond]
            if newfreqdist:
                result[cond] = newfreqdist
        return result

    # @total_ordering doesn't work here, since the class inherits from a builtin class
mutate cfg in place
dataset/ETHPy150Open nltk/nltk/nltk/probability.py/ConditionalFreqDist.__and__--crossover with--dataset/ETHPy150Open jansel/opentuner/opentuner/search/globalGA.py/GlobalEvolutionaryTechnique.mutation