src/dual-listbox.js
/**
     * Action to set one listItem to selected.
     */
Action to set one listItem to selected.
Action to set one listItem to selected .
_actionItemSelected(event) {
        event.preventDefault();
        let selected = this.dualListbox.querySelector(`.${SELECTED_MODIFIER}`);
        if (selected) {
            this.addSelected(selected);
        }
    }
_actionItemSelected ( event ) { event . preventDefault ( ) ; let selected = this . dualListbox . querySelector ( ` ${ SELECTED_MODIFIER } ` ) ; if ( selected ) { this . addSelected ( selected ) ; } }
Action to set one listItem to selected.
Action to set one listItem to selected .