refactor host setup helper

tests/utils.py

@@ -1,6 +1,8 @@
-import asyncio
-
 from contextlib import suppress
+import asyncio
+import multiaddr
+
+from libp2p import new_node
 
 
 async def cleanup():
@@ -12,3 +14,18 @@ async def cleanup():
         # Cancelled task raises asyncio.CancelledError that we can suppress:
         with suppress(asyncio.CancelledError):
             await task
+
+async def set_up_nodes_by_transport_opt(transport_opt_list):
+    nodes_list = []
+    for transport_opt in transport_opt_list:
+        node = await new_node(transport_opt=transport_opt)
+        await node.get_network().listen(multiaddr.Multiaddr(transport_opt[0]))
+        nodes_list.append(node)
+    return tuple(nodes_list)
+
+async def echo_stream_handler(stream):
+    while True:
+        read_string = (await stream.read()).decode()
+
+        resp = "ack:" + read_string
+        await stream.write(resp.encode())