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