how to get favicon with Goutte php

function getFavicon($url){
    # make the URL simpler
    $elems = parse_url($url);
    $url = $elems['scheme'].'://'.$elems['host'];

    # load site
    $output = file_get_contents($url);

    # look for the shortcut icon inside the loaded page
    $regex_pattern = "/rel=\"shortcut icon\" (?:href=[\'\"]([^\'\"]+)[\'\"])?/";
    preg_match_all($regex_pattern, $output, $matches);

    if(isset($matches[1][0])){
        $favicon = $matches[1][0];

        # check if absolute url or relative path
        $favicon_elems = parse_url($favicon);

        # if relative
        if(!isset($favicon_elems['host'])){
            $favicon = $url . '/' . $favicon;
        }

        return $favicon;
    }

    return false;
}