* [WIP] testvisualizationhook

* add TestNaiveVisualizationHook

* fix comment

* unpad

* batch imdenormalize

* fix comment

* fix comment

* [Feature] Add checkpoint helper

* minor fix

* add comments and fix format

* add hub directory

* add missing docstring

* add mmddp

* update

* update code

* update unittest

* fix comment

* [Feature]: Add optimzier and constructor.

* refactor unit tests

* add optimizer doc

* add parrots wrapper

* add parrots wrapper

* solve comments

* resolve comments

* move fileio directory from utils

* remove CephBackend from fileio and clear some deprecated docstring

* fix format

* fix a spellling error

* tmp add fileio

* ignore fileio mypy check error