Since HONEYCOMB-386, writer does not have to implement update.

In that case update is split into delete and create.

Delete is handled first then create.

But FlatRegistry.getParentDataObjectUpdate which wraps updates into parent node would

be invoked twice

and each invocation would include both changes (delete and create).

As a result writer.processModification would be invoked twice with the same update for parent node.

Possible solution:

remove child node updates from list of all updates while constructing parent update in FlatRegistry.getParentDataObjectUpdat