* add DAG test case
* fix datarace by adjusting theposition of lock
* polish code
* fix pytest for middleware
* remove test
Co-authored-by: Ziyue Jiang <ziyue.jiang@gmail.com>
* add DAG to split_module
* add comment
* add test case for DAG
* remove print
* add DAG middleware in scheduler
* add test case for scheduler
* remove break
* recover old lifecycle
Co-authored-by: Ziyue Jiang <ziyue.jiang@gmail.com>