code: def get_navigation(self, request, **kwargs):
          
  
          if self.navigation == self.parent_attr:
              if self.parent:
                  return self.parent.get_navigation(request, **kwargs)
              return ()
          else:
              return self._nav_from_tuple(request, self.navigation,
                                  **kwargs)
docs: Generates a list of tuples based on the values
          in `self.navigation` that are the side navigation links
          for this bundle. The tuple format is (url, title).