Type Definition pallet_session::historical::pallet::HistoricalSessions

pub type HistoricalSessions<T: Config> = StorageMap<_GeneratedPrefixForStorageHistoricalSessions<T>, Twox64Concat, SessionIndex, (T::Hash, ValidatorCount), OptionQuery>;

Mapping from historical session indices to session-data root hash and validator count.

Storage type is StorageMap with key type SessionIndex and value type (T :: Hash, ValidatorCount).