fetch method
Fetch the item with the given id
from the API.
Implementers should ensure this method updates the cache.
Implementation
@override
Future<Integration> fetch(Snowflake id) async {
final integrations = await list();
return integrations.firstWhere(
(integration) => integration.id == id,
orElse: () => throw IntegrationNotFoundException(guildId, id),
);
}