diff --git a/src/xdist/workermanage.py b/src/xdist/workermanage.py
index 440c5a5..a8a8993 100644
--- a/src/xdist/workermanage.py
+++ b/src/xdist/workermanage.py
@@ -96,7 +96,9 @@ class NodeManager:
         self.config.hook.pytest_xdist_setupnodes(config=self.config, specs=self.specs)
         self.trace("setting up nodes")
         with ThreadPoolExecutor(max_workers=len(self.specs)) as executor:
-            futs = [executor.submit(self.setup_node, spec, putevent) for spec in self.specs]
+            futs = [
+                executor.submit(self.setup_node, spec, putevent) for spec in self.specs
+            ]
             return [f.result() for f in futs]
 
     def setup_node(