Apparently the current MindMap has got basic features (useful and thanks), however it lacks a feature to write a line, a sort of link, over the hierarchy although of course we can write lines down the hierarchy as stems.
from https://en.wikipedia.org/wiki/File:MindMapGuidlines.svg
On the top left of an example above, two lines from Links are outside the hierarchy and work as links.
Is it possible to implement it on the PlantUML's MindMap?