* [Feature]: Add optimzier and constructor.

* refactor unit tests

* add optimizer doc

* add parrots wrapper

* add parrots wrapper

* solve comments

* resolve comments

* [Feature]: Add parameter schedulers.

* update

* update

* update

* update

* add docstring to lr and momentum

* resolve comments

* tmp

* add scheduler unit test

* disable yapf

* add more test

* add more test

* not use torch test case

* solve comments

* update file

* add more unit tests

* resolve comments

* update cosine ut

* fix typo

* solve comments

* solve comments

* resolve comments