def __setitem__(self, key, value):
        if self not in key:
            self.__keys.append(key)
        dict.__setitem__(self, key, value)
dataset/ETHPy150Open OpenMDAO/OpenMDAO-Framework/openmdao.lib/src/openmdao/lib/casehandlers/pymongo_bson/son.py/SON.__setitem__/swapped operands of `not in`