parseSelectors example

 else {
                $parts[] = "'$string'";
                break;
            }
        }

        return sprintf('concat(%s)', implode(', ', $parts));
    }

    public function cssToXPath(string $cssExpr, string $prefix = 'descendant-or-self::'): string
    {
        $selectors = $this->parseSelectors($cssExpr);

        /** @var SelectorNode $selector */
        foreach ($selectors as $index => $selector) {
            if (null !== $selector->getPseudoElement()) {
                throw new ExpressionErrorException('Pseudo-elements are not supported.');
            }

            $selectors[$index] = $this->selectorToXPath($selector, $prefix);
        }

        return implode(' | ', $selectors);
    }