code: def get_parent(self):
          
          if self.is_entity():
              return self.get_index_url(**self.default_kwargs_for_urls())
          elif self._parent is not None:
              resource = self._parent.rsplit('_', 1)[0]
              parts = self.default_kwargs_for_urls()
  
              if '{}_id'.format(resource) in parts:
                  id = parts.pop('{}_id'.format(resource))
                  parts['id'] = id
              return self.get_full_url(
                  self.app.reverse(
                      self._parent, **parts
                  )
              )
docs: Returns the url to the parent endpoint.