code: def insert_route(self, path, data, destroy_data_fn):
          
          return lib.ztrie_insert_route(self._as_parameter_, path, data, destroy_data_fn)
docs: Inserts a new route into the tree and attaches the data. Returns -1
  if the route already exists, otherwise 0. This method takes ownership of
  the provided data if a destroy_data_fn is provided.