moodle/mod/feedback/item/feedback_item_form_class.php

<?php

require_once $CFG->libdir.'/formslib.php';

define('FEEDBACK_ITEM_NAME_TEXTBOX_SIZE', 80);
define('FEEDBACK_ITEM_LABEL_TEXTBOX_SIZE', 20);
abstract class feedback_item_form extends moodleform {
    function get_item_form() {
        return $this->_form;
    }
}