Add the missing tests

tests/network/conftest.py

@@ -0,0 +1,14 @@
+import asyncio
+
+import pytest
+
+from tests.factories import net_stream_pair_factory
+
+
+@pytest.fixture
+async def net_stream_pair():
+    stream_0, host_0, stream_1, host_1 = await net_stream_pair_factory()
+    try:
+        yield stream_0, stream_1
+    finally:
+        await asyncio.gather(*[host_0.close(), host_1.close()])