code: def strip_dbm_antsignal(self, idx):
          
          dbm_antsignal, = struct.unpack_from('<b', self._rtap, idx)
          return idx + 1, dbm_antsignal
docs: strip(1 byte) radiotap.dbm.ant_signal
          :idx: int
          :return: int
              idx
          :return: int