code: def strip_chan(self, idx):
          
          chan = collections.namedtuple(
              'chan', ['freq', 'turbo', 'cck', 'ofdm', 'two_g', 'five_g',
                       'passive', 'dynamic', 'gfsk', 'gsm', 'static_turbo',
                       'half_rate', 'quarter_rate'])
  
          idx = Radiotap.align(idx, 2)
          freq, flags, = struct.unpack_from('<HH', self._rtap, idx)
          chan.freq = freq
  
          bits = format(flags, '016b')[::-1]
          chan.turbo = int(bits[4])
          chan.cck = int(bits[5])
          chan.ofdm = int(bits[6])
          chan.two_g = int(bits[7])
          chan.five_g = int(bits[8])
          chan.passive = int(bits[9])
          chan.dynamic = int(bits[10])
          chan.gfsk = int(bits[11])
          chan.gsm = int(bits[12])
          chan.static_turbo = int(bits[13])
          chan.half_rate = int(bits[14])
          chan.quarter_rate = int(bits[15])
          return idx + 4, chan
docs: strip(2 byte) radiotap.channel.flags
          :idx: int
          :return: int
              idx
          :return: collections.namedtuple