public function serializeOperations()
    {
        $datas = array();

        foreach ($this->operations as $operation) {
            $method = $operation[0];
            $args = $operation[1];

            foreach ($args as &$arg) {
                if ($arg instanceof self) {
                    $arg = $arg->getHash();
                }
            }

            $datas[] = array($method, $args);
        }

        return serialize($datas);
    }