Fix lint

core/state/statedb.go

@@ -764,6 +764,7 @@ func (db *DB) AddReward(validator common.Address, reward *big.Int) error {
 	return db.UpdateStakingInfo(validator, wrapper)
 }
 
+// CollectReward moves the rewards into the delegator's normal balance.
 func (db *DB) CollectReward(delegator common.Address) {
 	//TODO: implement collect reward logic
 	// The reward will be withdrawn to the delegator's address balance as a whole.

core/state_transition.go

@@ -394,6 +394,7 @@ func (st *StateTransition) applyDelegateTx(delegate *staking.Delegate) error {
 				// Firstly use the tokens in undelegation to delegate (redelegate)
 				undelegateAmount := big.NewInt(0).Set(delegate.Amount)
 				// Use the latest undelegated token first as it has the longest remaining locking time.
+				// TODO: always order the list by epoch.
 				i := len(delegation.Entries) - 1
 				for ; i >= 0; i-- {
 					if delegation.Entries[i].Amount.Cmp(undelegateAmount) <= 0 {