fix lint

Author: kwen2501

examples/all_reduce.py

@@ -248,7 +248,7 @@ def test(N: int, device: torch.device, dtype: torch.dtype) -> None:
     rank = dist.get_rank()
 
     # Create symmetric memory tensor for Helion implementation
-    symm_mem.enable_symm_mem_for_group(dist.group.WORLD.group_name)
+    symm_mem.enable_symm_mem_for_group(dist_group.group_name)
     a_shared = symm_mem.empty(N // world_size, dtype=dtype, device=device).normal_()
 
     # Create symmetric memory tensor for reference implementation