private function parseDirectives($isConst)
    {
        $directives = [];
        while ($this->peek(Token::AT)) {
            $directives[] = $this->parseDirective($isConst);
        }

        return new NodeList($directives);
    }
private function parseDirectives($isConst)
    {
        $directives = [];
        while ($this->peek(Token::AT)) {
            $directives[] = $this->parseDirective($isConst);
        }

        return new NodeList($directives);
    }
@param bool $isConst

@return DirectiveNode[]|NodeList

@throws SyntaxError