private void handleAdd(ItemListSuggestBox<UserId> suggestBox, SharingSettingsDropDown lb, TextArea addPeopleTextArea) {
Set<UserId> items = suggestBox.getItems();
items.removeAll(getUsersInSharingSettingsList());
List<UserSharingSetting> listDataItems = new ArrayList<UserSharingSetting>(sharingSettingsList.getListData());
for(UserId item : items) {
listDataItems.add(new UserSharingSetting(item, lb.getSelectedItem()));
}
addPeopleTextArea.setText("");
sharingSettingsList.setListData(listDataItems);
}