NegationNode example

$argument, $argumentPseudoElement] = $this->parseSimpleSelector($stream, true);
                    $next = $stream->getNext();

                    if (null !== $argumentPseudoElement) {
                        throw SyntaxErrorException::pseudoElementFound($argumentPseudoElement, 'inside ::not()');
                    }

                    if (!$next->isDelimiter([')'])) {
                        throw SyntaxErrorException::unexpectedToken('")"', $next);
                    }

                    $result = new Node\NegationNode($result, $argument);
                } else {
                    $arguments = [];
                    $next = null;

                    while (true) {
                        $stream->skipWhitespace();
                        $next = $stream->getNext();

                        if ($next->isIdentifier()
                            || $next->isString()
                            || $next->isNumber()
                            

namespace Symfony\Component\CssSelector\Tests\Node;

use Symfony\Component\CssSelector\Node\ClassNode;
use Symfony\Component\CssSelector\Node\ElementNode;
use Symfony\Component\CssSelector\Node\NegationNode;

class NegationNodeTest extends AbstractNodeTestCase
{
    public static function getToStringConversionTestData()
    {
        return [
            [new NegationNode(new ElementNode(), new ClassNode(new ElementNode(), 'class')), 'Negation[Element[*]:not(Class[Element[*].class])]'],
        ];
    }

    public static function getSpecificityValueTestData()
    {
        return [
            [new NegationNode(new ElementNode(), new ClassNode(new ElementNode(), 'class')), 10],
        ];
    }
}