private function append(Header $header)
    {
        if ($this->children) {
            $latest = \end($this->children);
            if ($latest->userLevel < $header->userLevel) {
                $latest->append($header);
                return;
            }
        }
        $this->children[] = $header;
        $header->parent = $this;
    }
private function append(Header $header)
    {
        if ($this->children) {
            $latest = \end($this->children);
            if ($latest->userLevel < $header->userLevel) {
                $latest->append($header);
                return;
            }
        }
        $this->children[] = $header;
        $header->parent = $this;
    }
private function append ( Header $ header ) { if ( $ this -> children ) { $ latest = \ end ( $ this -> children ) ; if ( $ latest -> userLevel < $ header -> userLevel ) { $ latest -> append ( $ header ) ; return ; } } $ this -> children [ ] = $ header ; $ header -> parent = $ this ; }
Only in use at built time, append the child at the right place in the tree
Only in use at built time append the child at the right place in the tree