type Book @key(fields: "id language country name desc") @extends {
id: ID! @external
language: String! @external
country: String @external
name: String! @external
description: String! @external
information: MetaInformation @requires(fields: "id language country name desc ")
}
here I extended book with information property and other ones are coming from Book graph, I want to know how I can set default value for country? It can be null in Book graph but it requires for fetching information property or somehow I should handle it in datafetcher.