private function retrieveNode(string ...$nodePath)
    {
        $node = $this->comprobante;
        foreach ($nodePath as $level) {
            if (! isset($node->{$level})) {
                return null;
            }
            $node = $node->{$level};
        }
        return $node;
    }
private function retrieveNode(string ...$nodePath)
    {
        $node = $this->comprobante;
        foreach ($nodePath as $level) {
            if (! isset($node->{$level})) {
                return null;
            }
            $node = $node->{$level};
        }
        return $node;
    }
private function retrieveNode ( string ... $ nodePath ) { $ node = $ this -> comprobante ; foreach ( $ nodePath as $ level ) { if ( ! isset ( $ node -> { $ level } ) ) { return null ; } $ node = $ node -> { $ level } ; } return $ node ; }
Private helper to locate a node
@see node(), attribute()
@param string[] ...$nodePath
@return null|SimpleXMLElement
Private helper to locate a node