pub fn process_all_players_for_account<E, F>(
    games: &mut RwLockWriteGuard<'static, RawRwLock, HashMap<Arc<InstanceName>, InstanceRef, RandomState>>,
    acctid: AccountId,
    f: F
) -> Result<(), E> where
    E: Error,
    F: for<'_, '_> FnMut(&mut InstanceGuard<'_>, PlayerId) -> Result<(), E>,