public function getParent()
    {
        if ($this->isRoot()) {
            return null;
        }

        return substr($this->subject->getFullPath(), 0, strrpos($this->subject->getFullPath(), '/'));
    }
public function getParent()
    {
        if ($this->isRoot()) {
            return null;
        }

        return substr($this->subject->getFullPath(), 0, strrpos($this->subject->getFullPath(), '/'));
    }
public function getParent ( ) { if ( $ this -> isRoot ( ) ) { return null ; } return substr ( $ this -> subject -> getFullPath ( ) , 0 , strrpos ( $ this -> subject -> getFullPath ( ) , '/' ) ) ; }
get the current tree parent, null if root

@return null|string
get the current tree parent null if root