[Streaming] Streaming Cross-Lang API (#7464)

streaming/python/tests/test_serialization.py

@@ -0,0 +1,13 @@
+from ray.streaming.runtime.serialization import CrossLangSerializer
+from ray.streaming.message import Record, KeyRecord
+
+
+def test_serialize():
+    serializer = CrossLangSerializer()
+    record = Record("value")
+    record.stream = "stream1"
+    key_record = KeyRecord("key", "value")
+    key_record.stream = "stream2"
+    assert record == serializer.deserialize(serializer.serialize(record))
+    assert key_record == serializer.\
+        deserialize(serializer.serialize(key_record))