Type Alias Ledger 

pub type Ledger<T: Config> = StorageMap<_GeneratedPrefixForStorageLedger<T>, Blake2_128Concat, T::AccountId, StakingLedger<T>>;

Map from all (unlocked) “controller” accounts to the info regarding the staking.

Note: All the reads and mutations to this storage MUST be done through the methods exposed by StakingLedger to ensure data and lock consistency.

Storage type is StorageMap with key type T :: AccountId and value type StakingLedger < T >.

Aliased Type

pub struct Ledger<T: Config>(/* private fields */);