def get_scheme(self, rel_key):
        relation_args = {
            'userName': rel_key.user,
            'programName': rel_key.program,
            'relationName': rel_key.relation
        }
        if not self.connection:
            raise RuntimeError(
                rel_key % "no schema for relation %s because no connection")
        try:
            dataset_info = self.connection.dataset(relation_args)
        except MyriaError:
            raise ValueError('No relation {} in the catalog'.format(rel_key))
        schema = dataset_info['schema']
        return scheme.Scheme(zip(schema['columnNames'], schema['columnTypes']))
dataset/ETHPy150Open uwescience/raco/raco/backends/myria/catalog.py/MyriaCatalog.get_scheme/swapped operands of `%`