WC_Install::parse_update_notice PHP Method

    private static function parse_update_notice($content, $new_version)
    {
        // Output Upgrade Notice.
        $matches = null;
        $regexp = '~==\\s*Upgrade Notice\\s*==\\s*=\\s*(.*)\\s*=(.*)(=\\s*' . preg_quote(WC_VERSION) . '\\s*=|$)~Uis';
        $upgrade_notice = '';
        if (preg_match($regexp, $content, $matches)) {
            $version = trim($matches[1]);
            $notices = (array) preg_split('~[\\r\\n]+~', trim($matches[2]));
            // Check the latest stable version and ignore trunk.
            if ($version === $new_version && version_compare(WC_VERSION, $version, '<')) {
                $upgrade_notice .= '<div class="wc_plugin_upgrade_notice">';
                foreach ($notices as $index => $line) {
                    $upgrade_notice .= wp_kses_post(preg_replace('~\\[([^\\]]*)\\]\\(([^\\)]*)\\)~', '<a href="${2}">${1}</a>', $line));
                }
                $upgrade_notice .= '</div> ';
            }
        }
        return wp_kses_post($upgrade_notice);
    }