public function __construct($scheme, $userinfo, $host, $port, $path, $query, $fragment)
{
$this->scheme = is_null($scheme) || ctype_lower($scheme) ? $scheme : strtolower($scheme);
$this->userinfo = $userinfo;
$this->host = $host;
$this->port = is_null($port) ? $port : (int) $port;
$this->path = $path;
$this->query = $query;
$this->fragment = $fragment;
}