Add missing required arg to _append_client_metadata

Author: aclark4life

libs/langchain-mongodb/langchain_mongodb/agent_toolkit/database.py

@@ -62,7 +62,7 @@ def __init__(
         self._sample_docs_in_coll_info = sample_docs_in_collection_info
         self._indexes_in_coll_info = indexes_in_collection_info
 
-        _append_client_metadata(self._client)
+        _append_client_metadata(self._client, DRIVER_METADATA)
 
     @classmethod
     def from_connection_string(