def _process_null_filters(self, filters):
        result = copy.deepcopy(filters)

        null_filters = {k: v for k, v in six.iteritems(filters)
                        if v is None or (type(v) in [str, unicode] and str(v.lower()) == 'null')}

        for key in null_filters.keys():
            result[(key) % '%s__exists'] = False
            del result[key]

        return result
dataset/ETHPy150Open StackStorm/st2/st2common/st2common/models/db/__init__.py/MongoDBAccess._process_null_filters/swapped operands of `%`