### What problem does this PR solve?
As title
### Type of change
- [x] Documentation Update
- [x] Refactoring
Signed-off-by: Jin Hai <haijin.chn@gmail.com>
### What problem does this PR solve?
- typos
- IDE warnings
### Type of change
- [x] Refactoring
---------
Signed-off-by: Jin Hai <haijin.chn@gmail.com>