public function domain($domain = null)
    {
        if (is_null($domain)) {
            return $this->getDomain();
        }

        $this->action['domain'] = $domain;

        return $this;
    }
public function domain($domain = null)
    {
        if (is_null($domain)) {
            return $this->getDomain();
        }

        $this->action['domain'] = $domain;

        return $this;
    }
public function domain ( $ domain = null ) { if ( is_null ( $ domain ) ) { return $ this -> getDomain ( ) ; } $ this -> action [ 'domain' ] = $ domain ; return $ this ; }
Get or set the domain for the route.

@param  string|null  $domain
@return $this|string|null
Get or set the domain for the route .