isDelimiter example

    }

    private function parseSelectorList(TokenStream $stream): array
    {
        $stream->skipWhitespace();
        $selectors = [];

        while (true) {
            $selectors[] = $this->parserSelectorNode($stream);

            if ($stream->getPeek()->isDelimiter([','])) {
                $stream->getNext();
                $stream->skipWhitespace();
            } else {
                break;
            }
        }

        return $selectors;
    }

    private function parserSelectorNode(TokenStream $stream): Node\SelectorNode
    {

    public function getNextIdentifierOrStar(): ?string
    {
        $next = $this->getNext();

        if ($next->isIdentifier()) {
            return $next->getValue();
        }

        if ($next->isDelimiter(['*'])) {
            return null;
        }

        throw SyntaxErrorException::unexpectedToken('identifier or "*"', $next);
    }

    /** * Skips next whitespace if any. */
    public function skipWhitespace(): void
    {