From 7d3f2ca3ed13863afaf1af59d8c07d4ae766a6fe Mon Sep 17 00:00:00 2001
From: Nuno Campos <nuno@langchain.dev>
Date: Sat, 19 Oct 2024 15:11:18 -0700
Subject: [PATCH] Lint

---
 libs/langgraph/langgraph/pregel/executor.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libs/langgraph/langgraph/pregel/executor.py b/libs/langgraph/langgraph/pregel/executor.py
index 2b627df2e..246510fb4 100644
--- a/libs/langgraph/langgraph/pregel/executor.py
+++ b/libs/langgraph/langgraph/pregel/executor.py
@@ -124,7 +124,9 @@ class AsyncBackgroundExecutor(AsyncContextManager):
         self.sentinel = object()
         self.loop = asyncio.get_running_loop()
         if max_concurrency := config.get("max_concurrency"):
-            self.semaphore = asyncio.Semaphore(max_concurrency)
+            self.semaphore: Optional[asyncio.Semaphore] = asyncio.Semaphore(
+                max_concurrency
+            )
         else:
             self.semaphore = None