Neos\Neos\Service\LinkingService::getScheme PHP Method

    public function getScheme($uri)
    {
        if ($uri instanceof Uri) {
            return $uri->getScheme();
        }
        if (preg_match(self::PATTERN_SUPPORTED_URIS, $uri, $matches) === 1) {
            return $matches[1];
        }
        return '';
    }

 /**
  * @param string|Uri $uri
  * @return string
  */
 public function getScheme($uri)
 {
     return $this->linkingService->getScheme($uri);
 }