Function full_conflicted_set 

async fn full_conflicted_set<AuthSets>(
    rules: &RoomVersionRules,
    conflicted_states: ConflictMap<OwnedEventId>,
    auth_sets: AuthSets,
    fetch: impl FetchEvent,
    hydra_backports: bool,
) -> Result<HashSet<OwnedEventId, RandomState>>
where
    AuthSets: Stream<Item = AuthSet<OwnedEventId>> + Send,