/**
* @param string $pattern
* @param IUrl $url
* @param string $key
*
* @return string
*/
protected function setProtocol($pattern, IUrl $url, $key = ':scheme')
{
$scheme = $url->getProtocol();
if ($scheme) {
$scheme = s('%s://', $scheme);
}
$pattern = s($pattern, [$key => $scheme]);
return $pattern;
}