@classmethod
    def _expr_big_minus(cls, x, n):
        raise NotImplementedError
Returns a dictionary where each key is associated with a list of values.
dataset/ETHPy150Open sympy/sympy/sympy/functions/special/hyper.py/HyperRep._expr_big_minus--crossover with--dataset/ETHPy150Open benoitc/restkit/restkit/datastructures.py/MultiDict.dict_of_lists