public function addHeader(string $key, string $value): Response
    {
        $this->headers->add($key, $value);
        return $this;
    }
public function addHeader(string $key, string $value): Response
    {
        $this->headers->add($key, $value);
        return $this;
    }
public function addHeader ( string $ key , string $ value ) : Response { $ this -> headers -> add ( $ key , $ value ) ; return $ this ; }
Add a header
Allows for adding multiple headers with the same key

@param string $key
@param string $value
@return \sndsgd\http\Response
Add a header Allows for adding multiple headers with the same key