def ledger.lend
import bend-kit-camber@0.15.0.1/camber.bend as Camberimport Base
import bend-kit-resources@0.1.0.0/resources.bend as Res
210# None means the pool has no free unit for a resource the owner still holds.
211def ledger.lend(ledger: Ledger) -> Maybe<&1, Ledger>:
212 Ledger{pool, lent, completed, rejected} = ledger
213 ledger.took(Res.reserve(pool, 1n), lent, completed, rejected)