unselectWhere method
De-selects items matching predicate.
Implementation
void unselectWhere(bool Function(M3EDropdownItem<T>) predicate) {
for (var i = 0; i < _items.length; i++) {
if (predicate(_items[i]) && _items[i].selected) {
_items[i] = _items[i].copyWith(selected: false);
}
}
_reapplySearchFilter();
notifyListeners();
onSelectionChange?.call(selectedItems);
}