def _get_shift_key(self, ctx):
        try:
            return self._shift_keys[ctx._id_obj]
        except __HOLE__:
            pass

        # create the net shift of self and the context's shift set (applying
        # self to the ctx's shift set so any re-shifted nodes take the values
        # from the shift set).
        net_shift_set = cython.declare(dict)
        net_shift_set = dict(ctx._shift_set)
        net_shift_set.update(self)

        # get the shift key and add it to the cache
        shift_key = _make_shift_key(net_shift_set)
        self._shift_keys[ctx._id_obj] = shift_key
        return shift_key
dataset/ETHPy150Open manahl/mdf/mdf/context.py/ShiftSet._get_shift_key