code: public final void request(Result<I> result)
    {
      I instance = _instance;
      
      if (instance != null && _lifecycle.isActive() && ! isModified()) {
        result.ok(instance);
      }
      else if (_lifecycle.isDestroyed()) {
        result.ok(null);
      }
      else {
        _strategy.request(this, result);
      }
    }
docs: Returns the instance for a top-level request
  @return the request object or null for none.