public function question_preview_icon($quiz, $question, $label = null, $variant = null) {
        $url = quiz_question_preview_url($quiz, $question, $variant);

        // Do we want a label?
        $strpreviewlabel = '';
        if ($label) {
            $strpreviewlabel = ' ' . get_string('preview', 'quiz');
        }

        // Build the icon.
        $strpreviewquestion = get_string('previewquestion', 'quiz');
        $image = $this->pix_icon('t/preview', $strpreviewquestion);

        $action = new \popup_action('click', $url, 'questionpreview',
                                        question_preview_popup_params());

        return $this->action_link($url, $image . $strpreviewlabel, $action,
                array('title' => $strpreviewquestion, 'class' => 'preview'));
    }