code: def strip_tx_attenuation(self, idx):
          
          idx = Radiotap.align(idx, 2)
          tx_attenuation, = struct.unpack_from('<H', self._rtap, idx)
          return idx + 2, tx_attenuation
docs: strip(1 byte) tx_attenuation
          :idx: int
          :return: int
              idx
          :return: int