Update returns/primitives/reawaitable.py

Co-authored-by: sobolevn <mail@sobolevn.me>

Author: proboscis

returns/primitives/reawaitable.py

@@ -5,6 +5,8 @@
 
 class AsyncLock(Protocol):
     """A protocol for an asynchronous lock."""
+    
+    def __init__(self) -> None: ...
 
     async def __aenter__(self) -> None: ...