Grasshopper tree path with null item

I lofted a series of curves to form surfaces - some of them were unsuccessful and the path in the tree data showed null.
when I unrolled these surfaces, the tree data with the unrolled surfaces no longer had the paths with the null items.
in the example, surface index 49 was an unsuccessful attempt and branch path 49 is missing.
How can I reinsert a branch with nothing or null or an empty branch at branch path 49 so it forms a placeholder path?
Thanks (391.2 KB) treenullpathsmissing

thank you
that works!!

that works very well!!!