protected function getSiteId($sites, $site_name)
    {
        if ($site = $this->getSiteByName($sites, $site_name)) {
            return $site->id;
        }
        return null;
    }
protected function getSiteId($sites, $site_name)
    {
        if ($site = $this->getSiteByName($sites, $site_name)) {
            return $site->id;
        }
        return null;
    }
protected function getSiteId ( $ sites , $ site_name ) { if ( $ site = $ this -> getSiteByName ( $ sites , $ site_name ) ) { return $ site -> id ; } return null ; }
Get forge site id from site name.

@param $sites
@param $site_name
@return mixed
Get forge site id from site name .