addOption method
Add a option
to groupList.
If newGroup
is true, it will create a new group.
Implementation
void addOption(Option option, {bool newGroup = false}) {
final OptionGroup group;
if (groupList.isEmpty || newGroup) {
group = OptionGroup();
groupList.add(group);
} else {
group = groupList.last;
}
group.addOption(option);
}