 zhiyan  thanks for helping explanation  overall it is correct  and you are suggestion makes sense for me  will improve it in next ps iccha  actually  this patch is related to c in that patch  we are trying to set image size if the image is transferring from  queued  to  active  directly when user add update locations for the image  the try except can make sure we can iterate all the locations to get an available image  i improve it at here since it is breaking some unit test cases since we are introducing some new behaviour by this change  does it make sense for you 