$choices = array();
        $default = '';
        $select = $mform->addElement('select', '{{ id }}', get_string('{{ id }}', '{{ langCategory }}'), $choices);
        $mform->setDefault('{{ id }}', $default);
        $mform->setType('{{ id }}', PARAM_ALPHA);
        // Allow for multiple selection
        // $select->setMultiple(true);
        // With setSelected() you can provide several values to be selected.
        // $select->setSelected(array());
{% include 'form/form-common-element.twig' %}