code: def strip_xchannel(self, idx):
          
          xchannel = collections.namedtuple(
              'xchannel', ['flags', 'freq', 'channel', 'max_power'])
  
          flags = collections.namedtuple(
              'flags', ['turbo', 'cck', 'ofdm', 'two_g', 'five_g', 'passive',
                        'dynamic', 'gfsk', 'gsm', 'sturbo', 'hafl', 'quarter',
                        'ht_20', 'ht_40u', 'ht_40d'])
  
          idx = Radiotap.align(idx, 2)
          flag_val, freq, channel, max_power = struct.unpack_from('<lHBB', self._rtap, idx)
  
          xchannel.freq = freq
          xchannel.channel = channel
          xchannel.max_power = max_power
  
          bits = format(flag_val, '032b')[::-1]
          flags.turbo = int(bits[4])
          flags.cck = int(bits[5])
          flags.ofdm = int(bits[6])
          flags.two_g = int(bits[7])
          flags.five_g = int(bits[8])
          flags.passive = int(bits[9])
          flags.dynamic = int(bits[10])
          flags.gfsk = int(bits[11])
          flags.gsm = int(bits[12])
          flags.sturbo = int(bits[13])
          flags.half = int(bits[14])
          flags.quarter = int(bits[15])
          flags.ht_20 = int(bits[16])
          flags.ht_40u = int(bits[17])
          flags.ht_40d = int(bits[18])
          xchannel.flags = flags
  
          return idx + 8, xchannel
docs: strip(7 bytes) radiotap.xchannel.channel(1 byte),
          radiotap.xchannel.freq(2 bytes) and radiotap.xchannel.flags(4 bytes)
          :idx: int
          :return: int
              idx
          :return: collections.namedtuple