How to set TreeVertex.level manually ? Any example?

I want to know how to set TreeVertex.level manually. Is there any example ?
Thanks

I thought I provided a complete sample at How to bypass node level in GoJS?.

And there is the possible alternative requirement in the existing sample: http://gojs.net/latest/samples/parseTree.html

TreeLayout works on a tree-structured graph that is in a TreeNetwork composed of TreeVertexs and TreeEdges. It automatically computes the TreeVertex.level property based on the graph. But the code I gave you (posted in the other topic) adjusts the level based on the value of the data.band property.