code: def path_to_root(self, session=None, order=desc):
          
          table = self.__class__
          query = self._base_query_obj(session=session)
          query = query.filter(table.is_ancestor_of(self, inclusive=True))
          return self._base_order(query, order=order)
docs: Generate path from a leaf or intermediate node to the root.
  
          For example:
  
              node11.path_to_root()
  
              .. code::
  
                  level           Nested sets example
  
                                   -----------------------------------------
                  1               |    1(1)22                               |
                          ________|______|_____________________             |
                         |        |      |                     |            |
                         |         ------+---------            |            |
                  2    2(2)5           6(4)11      | --     12(7)21         |
                         |               ^             |   /      \         |
                  3    3(3)4       7(5)8   9(6)10      ---/----    \        |
                                                      13(8)16 |  17(10)20   |
                                                         |    |     |       |
                  4                                   14(9)15 | 18(11)19    |
                                                              |             |
                                                               -------------