addSelectedOption method
add selected option MultiSelectController is used to add selected option.
Implementation
void addSelectedOption(ValueItem<T> option) {
if (value._disabledOptions.contains(option)) {
throw Exception('Cannot select disabled option');
}
if (!value._options.contains(option)) {
throw Exception('Cannot select option that is not in the options list');
}
value._selectedOptions.add(option);
notifyListeners();
}