Update bot/retrievers/retrieve_similar_nodes.py

Add group_by_metadata validation

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

bot/retrievers/retrieve_similar_nodes.py

@@ -57,14 +57,11 @@ def query_db(
                 Note: This would completely disable the similarity search and
                 it would just return the results with no ordering.
                 default is `False`. If `True` the query will be ignored and no embedding of it would be fetched
-            aggregate_records : bool
-                aggregate records and group by a given term in `group_by_metadata`
-            group_by_metadata : list[str]
-                do grouping by some property of `metadata_`
-        """
         ignore_sort = kwargs.get("ignore_sort", False)
         aggregate_records = kwargs.get("aggregate_records", False)
         group_by_metadata = kwargs.get("group_by_metadata", [])
+        if not isinstance(group_by_metadata, list):
+            raise ValueError("Expected 'group_by_metadata' to be a list.")
         self._vector_store._initialize()
 
         if not aggregate_records: