77     private ?string $scheme = null;  variable in ComboStrap\\Web\\Url
125             $this->scheme = $urlComponents["scheme"] ?? null;
313         if ($this->scheme === null) {
316         return $this->scheme;
567     public function setScheme(string $scheme): Url  argument
569         $this->scheme = $scheme;
751             $scheme = $this->getScheme();
753             $scheme = null;
757         switch ($scheme) {
762                 $base = "$scheme://";
785                 $base = "$scheme:";
818                     $scheme = $this->getScheme();
820                     $scheme = null;
832                     if ($scheme !== null) {
833                         $base = "{$scheme}://";
842                     if (!in_array($scheme, self::RELATIVE_URL_SCHEMES) && $scheme !== null) {
843                         $base = "{$scheme}:";