public function host($host = null)
    {
        $this->host = empty($host) ? null : $host;

        return $this->host;
    }
public function host($host = null)
    {
        $this->host = empty($host) ? null : $host;

        return $this->host;
    }
public function host ( $ host = null ) { $ this -> host = empty ( $ host ) ? null : $ host ; return $ this -> host ; }
Sets host requirement

@param null|string $host

@return string
Sets host requirement