docs: def lookup_cmd(ops, cmd_id):
      """https://github.com/thom311/libnl/blob/libnl3_2_25/lib/genl/mngt.c#L33.
  
      Positional arguments:
      ops -- genl_ops class instance.
      cmd_id -- integer.
  
      Returns:
      genl_cmd class instance or None.
      """
      for i in range(ops.o_ncmds):
          cmd = ops.o_cmds[i]
          if cmd.c_id == cmd_id:
              return cmd
      return None