code: def as_list(self):
          
          result = []
          for child in self.children:
              self._depth_traversal(child, result)
  
          return result
docs: Returns a list of strings describing the full paths and patterns
          along with the name of the urls.  Example:
  
          .. code-block::python
              >>> u = URLTree()
              >>> u.as_list()
              [
                  'admin/',
                  'admin/$, name=index',
                  'admin/login/$, name=login',
              ]