PhpMigration\Changes\v7dot0\ParseDifference::afterTraverse PHP Method

    public function afterTraverse(array $nodes)
    {
        // Parse code as PHP 5
        try {
            $stmts = $this->parser5->parse($this->visitor->getCode());
        } catch (PhpParserError $e) {
            $this->addSpot('WARNING', true, 'Parse failed as PHP 5 "' . $e->getMessage() . '"', $e->getStartLine());
            return;
        }
        // Compare
        $this->ast2plain($stmts, $this->plain5);
        $this->normalizeNodeList($this->plain5);
        $this->normalizeNodeList($this->plain7);
        $diff = array_diff_assoc($this->plain5, $this->plain7);
        $lset = [];
        foreach ($diff as $i => $name) {
            // TODO we do like double-? in PHP 7 such as `$line = $this->lines[$i] ?? 0;`
            $line = isset($this->lines[$i]) ? $this->lines[$i] : 0;
            if (isset($lset[$line])) {
                continue;
            }
            $lset[$line] = true;
            $this->addSpot('WARNING', true, 'Different behavior between PHP 5/7', $line);
        }
    }