Function pallet_staking::slashing::do_slash

pub fn do_slash<T: Config>(
    stash: &T::AccountId, 
    value: BalanceOf<T>, 
    reward_payout: &mut BalanceOf<T>, 
    slashed_imbalance: &mut <<T as Config>::Currency as Currency<<T as Config>::AccountId>>::NegativeImbalance
)