private function parseDirective($isConst)
    {
        $start = $this->lexer->token;
        $this->expect(Token::AT);

        return new DirectiveNode([
            'name'      => $this->parseName(),
            'arguments' => $this->parseArguments($isConst),
            'loc'       => $this->loc($start),
        ]);
    }
private function parseDirective($isConst)
    {
        $start = $this->lexer->token;
        $this->expect(Token::AT);

        return new DirectiveNode([
            'name'      => $this->parseName(),
            'arguments' => $this->parseArguments($isConst),
            'loc'       => $this->loc($start),
        ]);
    }
@param bool $isConst

@return DirectiveNode

@throws SyntaxError