code: protected function chompScheme(&$url)
      {
          if (preg_match('#^([^/:]*):(//)(.*)#', $url, $matches)) {
              $url = $matches[2] . $matches[3];
  
              return $matches[1];
          }
  
          return false;
      }
docs: Extracts the scheme part of an incoming URL.
  
  @param string $url   URL so far. The scheme will be removed.
  
  @return string       Scheme part or false.