diff --git a/apis/python/src/tiledbsoma/_tdb_handles.py b/apis/python/src/tiledbsoma/_tdb_handles.py
index 24c4c2992a..c55e36a99d 100644
--- a/apis/python/src/tiledbsoma/_tdb_handles.py
+++ b/apis/python/src/tiledbsoma/_tdb_handles.py
@@ -332,6 +332,9 @@ def _opener(
         context: SOMATileDBContext,
         timestamp: int,
     ) -> clib.SOMAArray:
+        # Virtual method to implement _opener in derived classes 
+        # SOMADataFrameWrapper, SOMASparseNDArrayWrapper, and 
+        # SOMADenseNDArrayWrapper
         raise NotImplementedError
 
     # Covariant types should normally not be in parameters, but this is for