asyncio: Add BoundedSemaphore to export list in locks.__all__.
diff --git a/Lib/asyncio/locks.py b/Lib/asyncio/locks.py
index 4b0ce50..2d458a9 100644
--- a/Lib/asyncio/locks.py
+++ b/Lib/asyncio/locks.py
@@ -1,6 +1,6 @@
 """Synchronization primitives."""
 
-__all__ = ['Lock', 'Event', 'Condition', 'Semaphore']
+__all__ = ['Lock', 'Event', 'Condition', 'Semaphore', 'BoundedSemaphore']
 
 import collections