community[minor]: Add async methods to CassandraChatMessageHistory (#21975)

libs/community/tests/integration_tests/memory/test_memory_cassandra.py

@@ -1,6 +1,6 @@
 import os
 import time
-from typing import Optional
+from typing import Any, Optional
 
 from langchain.memory import ConversationBufferMemory
 from langchain_core.messages import AIMessage, HumanMessage
@@ -37,13 +37,15 @@ def _chat_message_history(
     # drop table if required
     if drop:
         session.execute(f"DROP TABLE IF EXISTS {keyspace}.{table_name}")
-    #
+
+    kwargs: Any = {} if ttl_seconds is None else {"ttl_seconds": ttl_seconds}
+
     return CassandraChatMessageHistory(
         session_id=session_id,
         session=session,
         keyspace=keyspace,
         table_name=table_name,
-        **({} if ttl_seconds is None else {"ttl_seconds": ttl_seconds}),
+        **kwargs,
     )