diff --git a/src/pubsub/pubsub/pubsub_library_v4.py b/src/pubsub/pubsub/pubsub_library_v4.py
index 59f2cfc..f7b32e0 100644
--- a/src/pubsub/pubsub/pubsub_library_v4.py
+++ b/src/pubsub/pubsub/pubsub_library_v4.py
@@ -116,6 +116,10 @@ class MinimalSubscriber(Node):
         self.msg = msg
         return
 
+    def has_msg(self):
+        # Check if a maessage has been received
+        return self.msg is not None
+
     def return_msg(self):
         return self.msg