function filter_call ($instance, $method, ...$args)
  {
    if (is_object ($instance)) {
      if (is_object ($instance) && method_exists ($instance, $method)) return $instance->$method (...$args);
      if (isset($instance[$method]) && is_callable ($instance[$method])) {
        $m = $instance[$method];
        return $m(...$args);
      }
    }
    return null;
  }