* add autocast wrapper

* fix docstring

* fix docstring

* fix compare version

* fix unit test

* fix incompatible arguments

* fix as comment

* fix unit test

* rename auto_cast to autocast

* [Fix] Fix ema state dict swapping in EMAHook.

* fix pt1.5 ut

* add more comments

* [Feature] Support EMA and SWA.

* add ema hook

* add avg model ut

* add more unit tests

* resolve comments

* fix warmup ema

* rename

* fix comments

* add assert

* fix typehint

* add comments