execute method
BANG OPERATOR ALERT
!
action cannot be null
because there is a default condition which returns true always.
Implementation
@override
execute() {
final Map<bool Function(), OUTPUT Function()> newChildren =
Map.from(children)..putIfAbsent(defaultCondition, () => defaultAction);
final condition = newChildren.keys.firstWhere((condition) => condition());
final action = newChildren[condition];
return action!();
}