docs: def _nl_list_add(obj, prev, next_):
      """https://github.com/thom311/libnl/blob/libnl3_2_25/include/netlink/list.h#L27.
  
      Positional arguments:
      obj -- nl_list_head class instance.
      prev -- nl_list_head class instance.
      next_ -- nl_list_head class instance.
      """
      prev.next_ = obj
      obj.prev = prev
      next_.prev = obj
      obj.next_ = next_