private function parseObject($isConst)
    {
        $start = $this->lexer->token;
        $this->expect(Token::BRACE_L);
        $fields = [];
        while (! $this->skip(Token::BRACE_R)) {
            $fields[] = $this->parseObjectField($isConst);
        }

        return new ObjectValueNode([
            'fields' => new NodeList($fields),
            'loc'    => $this->loc($start),
        ]);
    }
private function parseObject($isConst)
    {
        $start = $this->lexer->token;
        $this->expect(Token::BRACE_L);
        $fields = [];
        while (! $this->skip(Token::BRACE_R)) {
            $fields[] = $this->parseObjectField($isConst);
        }

        return new ObjectValueNode([
            'fields' => new NodeList($fields),
            'loc'    => $this->loc($start),
        ]);
    }
@param bool $isConst

@return ObjectValueNode