docs: def add_type(self, type: type, serialize: Callable[[Any], str], unserialize: Callable[[str], Any]) -> None:
          """
          Adds serialization support for a new type.
  
          :param type: The type to add support for.
          :param serialize: A callable that takes an object of type ``type`` and returns a string.
          :param unserialize: A callable that takes a string and returns an object of type ``type``.
          """
          self.types.append(HierarkeyType(type=type, serialize=serialize, unserialize=unserialize))