which one is all reduce test file~~

### Describe the issue

hello, I can successfully test AG RS A2A kernel, thank you very much;
however, I want to test all reduce kernel, which python file I can use?
or how can I modify some python file to test all reduce kernel


### Environment details

- Python 3.9 (suggest using virtual environment)
- CUDA 12.4
- Torch 2.4.1
- Clang 19
a100 * 8

No Python file, test, or entry point is named in the issue. Start by locating the repository's all-reduce kernel and its Python test or example entry point, then check whether the existing A2A test setup can exercise it with the stated Python, CUDA, Torch, and eight-A100 environment. Done means documenting the correct file or modification needed to run the all-reduce test.

Written by the indexing model from the issue text.