docs: def _vksdesc(d):
      '''
          d = {'a':1,'b':2,'c':2,'d':4}
          desc = _vksdesc(d)
          pobj(desc)
      '''
      pt = copy.deepcopy(d)
      seqs_for_del =[]
      vset = set({})
      for k in pt:
          vset.add(pt[k])
      desc = {}
      for v in vset:
          desc[v] = []
      for k in pt:
          desc[pt[k]].append(k)
      return(desc)