Vaadin excel export addon + TreeTable

The current Vaadin excel export add on works perfect for a Tree with multiple root nodes and children.

If a Tree has nested nodes, it misses out grouping and also omits out the nodes.

For ex:

+child 2
+one more child

In the above scenario, the excel export does not export the subchild1,subSubRoot and its children.

I did debug through the ExcelExport class and the addHierarchichalRow method seems to be considering only the rootIds.

Has anyone done something like above.

Thanks for looking into the post.