docs: def merge(self, routes):
          ''' Merge the routes of another :class:`Bottle` application or a list of
              :class:`Route` objects into this application. The routes keep their
              'owner', meaning that the :data:`Route.app` attribute is not
              changed. '''
          if isinstance(routes, Bottle):
              routes = routes.routes
          for route in routes:
              self.add_route(route)