Add priority queues to handle seqno

libp2p/pubsub/read_only_queue.py

@@ -0,0 +1,14 @@
+import asyncio
+
+class ReadOnlyQueue():
+    
+    def __init__(self, queue):
+        self.queue = queue
+
+    async def get(self):
+        """
+        Get the next item from queue, which has items in the format (priority, data)
+        :return: next item from the queue
+        """
+        return (await self.queue.get())[1]
+