Swift_Mime_SimpleMessage::getTopNestingLevel PHP Method

    private function getTopNestingLevel()
    {
        $highestLevel = $this->getNestingLevel();
        foreach ($this->getChildren() as $child) {
            $childLevel = $child->getNestingLevel();
            if ($highestLevel < $childLevel) {
                $highestLevel = $childLevel;
            }
        }
        return $highestLevel;
    }