checked/validated most of the unit tests. Traversal tests are left. Need to fix traversal functions interface. It computes correctly but the results are not returned correctly. Some of the assignment operations need to be checked
now ID indeed works for trees using traversal operation. Still need to do further test check traversal unit tests as well
traversal test is corrected, now need to give examples for FK, ID, FD
for some reason state info is not directed to console, it asks for the opretor <<, if it is in KDL namespace it works