HistoryQueryExecutor executes the history queries.

PeerLedger differs from the OrdererLedger in that PeerLedger locally maintain a bitmask that tells apart valid transactions from invalid ones.

PeerLedgerProvider provides handle to ledger instances.

QueryExecutor executes the queries Get* methods are for supporting KV-based data model.

TxSimulator simulates a transaction on a consistent snapshot of the 'as recent state as possible' Set* methods are for supporting KV-based data model.

ValidatedLedger represents the 'final ledger' after filtering out invalid transactions from PeerLedger.