I don't know, it doesn't feel like this is proper code. Referencing the
same object multiple times is just so much of a hassle and this code
looks pretty unsafe with all the unwraps.
In the end it turns out that I don't need a tree, but need to iterate
over all directories instead, which is again something quite hard for
me, because I don't know how to build iterators "manually".
MasterofJOKers