code: def strip_fhss(self, idx):
          
          fhss = collections.namedtuple('fhss', ['hopset', 'pattern'])
          fhss.hopset, fhss.pattern, = struct.unpack_from('<bb', self._rtap, idx)
          return idx + 2, fhss
docs: strip (2 byte) radiotap.fhss.hopset(1 byte) and
          radiotap.fhss.pattern(1 byte)
          :idx: int
          :return: int
              idx
          :return: collections.namedtuple