balanceAction method
Implementation
@override
Parser balanceAction() => super.balanceAction().map((each) {
final e = each as List;
return BalanceAction(
date: e.first as DateTime,
account: e.elementAt(2) as Account,
unit: e.elementAt(3) as Money,
comment: e.elementAt(4) as String,
metadata: e.elementAt(5) as Map<String, MetaValue>,
);
});