notAtTheStartOfASelector example

if (!$stream->getPeek()->isDelimiter(['('])) {
                    $result = new Node\PseudoNode($result, $identifier);
                    if ('Pseudo[Element[*]:scope]' === $result->__toString()) {
                        $used = \count($stream->getUsed());
                        if (!(2 === $used
                           || 3 === $used && $stream->getUsed()[0]->isWhiteSpace()
                           || $used >= 3 && $stream->getUsed()[$used - 3]->isDelimiter([','])
                           || $used >= 4
                                && $stream->getUsed()[$used - 3]->isWhiteSpace()
                                && $stream->getUsed()[$used - 4]->isDelimiter([','])
                        )) {
                            throw SyntaxErrorException::notAtTheStartOfASelector('scope');
                        }
                    }
                    continue;
                }

                $stream->getNext();
                $stream->skipWhitespace();

                if ('not' === strtolower($identifier)) {
                    if ($insideNegation) {
                        throw SyntaxErrorException::nestedNot();
                    }

'[*]', SyntaxErrorException::unexpectedToken('"|"', new Token(Token::TYPE_DELIMITER, ']', 2))->getMessage()],
            ['[foo|]', SyntaxErrorException::unexpectedToken('identifier', new Token(Token::TYPE_DELIMITER, ']', 5))->getMessage()],
            ['[#]', SyntaxErrorException::unexpectedToken('identifier or "*"', new Token(Token::TYPE_DELIMITER, '#', 1))->getMessage()],
            ['[foo=#]', SyntaxErrorException::unexpectedToken('string or identifier', new Token(Token::TYPE_DELIMITER, '#', 5))->getMessage()],
            [':nth-child()', SyntaxErrorException::unexpectedToken('at least one argument', new Token(Token::TYPE_DELIMITER, ')', 11))->getMessage()],
            ['[href]a', SyntaxErrorException::unexpectedToken('selector', new Token(Token::TYPE_IDENTIFIER, 'a', 6))->getMessage()],
            ['[rel:stylesheet]', SyntaxErrorException::unexpectedToken('operator', new Token(Token::TYPE_DELIMITER, ':', 4))->getMessage()],
            ['[rel=stylesheet', SyntaxErrorException::unexpectedToken('"]"', new Token(Token::TYPE_FILE_END, '', 15))->getMessage()],
            [':lang(fr', SyntaxErrorException::unexpectedToken('an argument', new Token(Token::TYPE_FILE_END, '', 8))->getMessage()],
            [':contains("foo', SyntaxErrorException::unclosedString(10)->getMessage()],
            ['foo!', SyntaxErrorException::unexpectedToken('selector', new Token(Token::TYPE_DELIMITER, '!', 3))->getMessage()],
            [':scope > div :scope header', SyntaxErrorException::notAtTheStartOfASelector('scope')->getMessage()],
        ];
    }

    public static function getPseudoElementsTestData()
    {
        return [
            ['foo', 'Element[foo]', ''],
            ['*', 'Element[*]', ''],
            [':empty', 'Pseudo[Element[*]:empty]', ''],
            [':BEfore', 'Element[*]', 'before'],
            [':aftER', 'Element[*]', 'after'],
            [