private static function convertGraphNodeDateTimesToStrings(array $data)
    {
        $date_format = 'Y-m-d H:i:s';
        $model_name = get_class(new static());
        if (property_exists($model_name, 'graph_node_date_time_to_string_format')) {
            $date_format = static::$graph_node_date_time_to_string_format;
        }

        foreach ($data as $key => $value) {
            if ($value instanceof \DateTime) {
                $data[$key] = $value->format($date_format);
            }
        }

        return $data;
    }