I think it returns a ```SuccessfulResponse``` with ```null```.
```
if (command.getCommandId() == ClusteredGetCommand.COMMAND_ID) {         
   ClusteredGetCommand clusteredGet = (ClusteredGetCommand) command;
   if (distributionManager.isAffectedByRehash(clusteredGet.getKey()))
      return UnsureResponse.INSTANCE;
   return SuccessfulResponse.create(returnValue);
}
```