diff --git a/examples/xgboost-comprehensive/utils.py b/examples/xgboost-comprehensive/utils.py
index 51a4bb16e5b8..05a5630dc771 100644
--- a/examples/xgboost-comprehensive/utils.py
+++ b/examples/xgboost-comprehensive/utils.py
@@ -241,10 +241,12 @@ def sample(
         criterion: Optional[Criterion] = None,
     ) -> List[ClientProxy]:
         """Sample a number of Flower ClientProxy instances."""
+
         # Block until at least num_clients are connected.
         if min_num_clients is None:
             min_num_clients = num_clients
         self.wait_for(min_num_clients)
+        
         # Sample clients which meet the criterion
         available_cids = list(self.clients)
         if criterion is not None: