src/dual-listbox.js
/**
     * @Private
     * Adds option to the selected of available list (depending on the data).
     */
@Private
Adds option to the selected of available list (depending on the data).
@Private Adds option to the selected of available list ( depending on the data ) .
_addOption(option) {
        let listItem = this._createListItem(option);
        if (option.selected) {
            this.selected.push(listItem);
        } else {
            this.available.push(listItem);
        }
    }
_addOption ( option ) { let listItem = this . _createListItem ( option ) ; if ( option . selected ) { this . selected . push ( listItem ) ; } else { this . available . push ( listItem ) ; } }
@Private
 Adds option to the selected of available list (depending on the data).
@Private Adds option to the selected of available list ( depending on the data ) .