protected function renderProgressBar($percent1, $percent2 = 0, $offset = 0)
    {
        $percent1 = round(max(1, $percent1));
        $offset = round(max(0, $offset));
        $offset = round(min(99, $offset));

        $output = '<div class="progress">';
        $output .= '<div class="progress-bar">';
        $output .= '<div class="progress-bar1" style="width: ' . $percent1 . '%; margin-left: ' . $offset . '%;"></div>';

        if ($percent2 > 0) {
            $percent2 = round(max(1, $percent2));
            if ($percent1 + $percent2 + $offset > 100) {
                // preventing line break in css progress bar if widths and margins are bigger than 100%
                $percent2 = 100 - $percent1 - $offset;
                $percent2 = max(0, $percent2);
            }
            $output .= '<div class="progress-bar2" style="width: ' . $percent2 . '%"></div>';
        }

        $output .= '</div>';
        $output .= '</div>';
        return $output;
    }