code: def _read_opt_none(self, code, *, desc):
          
          _type = self._read_opt_type(code)
          _size = self._read_unpack(1)
          _data = self._read_fileng(_size)
  
          opt = dict(
              desc=_IPv6_Opts_NULL.get(code, desc),
              type=_type,
              length=_size + 2,
              data=_data,
          )
  
          return opt
docs: Read IPv6_Opts unassigned options.
  
          Structure of IPv6_Opts unassigned options [RFC 8200]:
              +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
              |  Option Type  |  Opt Data Len |  Option Data
              +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
  
              Octets      Bits        Name                        Description
                0           0     ipv6_opts.opt.type          Option Type
                0           0     ipv6_opts.opt.type.value    Option Number
                0           0     ipv6_opts.opt.type.action   Action (00-11)
                0           2     ipv6_opts.opt.type.change   Change Flag (0/1)
                1           8     ipv6_opts.opt.length        Length of Option Data
                2          16     ipv6_opts.opt.data          Option Data