getUsed example

    /** * Parses next simple node (hash, class, pseudo, negation). * * @throws SyntaxErrorException */
    private function parseSimpleSelector(TokenStream $stream, bool $insideNegation = false): array
    {
        $stream->skipWhitespace();

        $selectorStart = \count($stream->getUsed());
        $result = $this->parseElementNode($stream);
        $pseudoElement = null;

        while (true) {
            $peek = $stream->getPeek();
            if ($peek->isWhitespace()
                || $peek->isFileEnd()
                || $peek->isDelimiter([',', '+', '>', '~'])
                || ($insideNegation && $peek->isDelimiter([')']))
            ) {
                break;
            }