rotect(_private->imp);      if (_private->rootObject && _private->rootObject->isValid())         _private->rootObject->gcUnprotect(_private->imp);      if (_private->rootObject)         _private->rootObject->deref();      if (_private->originRootObject)         _private->originRootObject->deref();      _private->rootObject = rootObject.leakRef();     _private->originRootObject = originRootObject.leakRef(); 