feat: add barrier to bagua.torch_api module (#698)

bagua/torch_api/__init__.py

@@ -2,9 +2,7 @@
 """
 The Bagua communication library PyTorch interface.
 """
-from distutils.errors import (
-    DistutilsPlatformError,
-)
+from distutils.errors import DistutilsPlatformError
 
 try:
     import torch
@@ -29,32 +27,33 @@
     init_process_group,
     send,
     recv,
-    broadcast,
-    reduce,
-    reduce_inplace,
-    gather,
-    gather_inplace,
-    scatter,
-    scatter_inplace,
-    allreduce,
-    allreduce_inplace,
     allgather,
     allgather_inplace,
+    allreduce,
+    allreduce_inplace,
     alltoall,
     alltoall_inplace,
     alltoall_v,
     alltoall_v_inplace,
+    barrier,
+    broadcast,
+    gather,
+    gather_inplace,
+    reduce,
+    reduce_inplace,
     reduce_scatter,
     reduce_scatter_inplace,
+    scatter,
+    scatter_inplace,
     ReduceOp,
 )
 from .distributed import BaguaModule  # noqa: F401
 from .tensor import BaguaTensor  # noqa: F401
 from .env import (  # noqa: F401
-    get_rank,
-    get_world_size,
     get_local_rank,
     get_local_size,
+    get_rank,
+    get_world_size,
 )
 from . import contrib  # noqa: F401
 from . import communication  # noqa: F401