public function domain($domain)
    {
        if (empty($domain) || trim($domain) !== $domain) {
            throw new Exception('Invalid domain "' . $domain . '"', 2);
        } else {
            $this->domain = $domain;
        }

        return $this;
    }
public function domain($domain)
    {
        if (empty($domain) || trim($domain) !== $domain) {
            throw new Exception('Invalid domain "' . $domain . '"', 2);
        } else {
            $this->domain = $domain;
        }

        return $this;
    }
public function domain ( $ domain ) { if ( empty ( $ domain ) || trim ( $ domain ) !== $ domain ) { throw new Exception ( 'Invalid domain "' . $ domain . '"' , 2 ) ; } else { $ this -> domain = $ domain ; } return $ this ; }
Define domain for group

@param string $domain
@throws \Inphinit\Experimental\Exception
@return \Inphinit\Experimental\Routing\Group
Define domain for group