def __getitem__(self, item):
        assert isinstance(item, Variable)
        for s in self:
            if item in s:
                return s
        #item is not found in any existing set.  so create a new set
        new = set([item])
        self.append(new)
        return new
Return quick summary, i.e. R style output
dataset/ETHPy150Open nltk/nltk/nltk/inference/nonmonotonic.py/SetHolder.__getitem__--crossover with--dataset/ETHPy150Open HHammond/kcbo/kcbo/statistical_tests/utils.py/StatisticalTest.summary