public static function highlightWord($content, $word, $markup = '<b>%s</b>')
    {
        $word = (array) $word;
        $content = strip_tags($content);
        $latest = null;
        foreach ($word as $needle) {
            preg_match_all("/".preg_quote($needle, '/')."+/i", $content, $matches);
            if (is_array($matches[0]) && count($matches[0]) >= 1) {
                foreach ($matches[0] as $match) {
                    // ensure if a word is found twice we don't replace again.
                    if ($latest === $match) {
                        continue;
                    }
                    $content = str_replace($match, sprintf($markup, $match), $content);
                    $latest = $match;
                }
            }
        }

        return $content;
    }