File doesn't exist [Retrack"

Dear author:

Thank you for your work!
Am just wondering why the relevant files mentioned in the README.md doesn't exist. 

`python ./tests/debug/launch_schema_retriever.py`

> For examples on how to use ReTraCkRetriever in your code base, please check /tests/debug/launch_schema_retriever.py and 

 [TRAIN.MD](https://github.com/microsoft/KC/blob/main/papers/ReTraCk/TRAIN.MD).
