public static function type_config_form($mform, $classname = 'repository') {
        parent::type_config_form($mform, $classname);
        $apikey = get_config('youtube', 'apikey');
        if (empty($apikey)) {
            $apikey = '';
        }

        $mform->addElement('text', 'apikey', get_string('apikey', 'repository_youtube'), array('value' => $apikey, 'size' => '40'));
        $mform->setType('apikey', PARAM_RAW_TRIMMED);
        $mform->addRule('apikey', get_string('required'), 'required', null, 'client');

        $mform->addElement('static', null, '',  get_string('information', 'repository_youtube'));
    }