code: def byte(self):
          
          flags = int(self._in_use) << 7 \
              | int(self._controller) << 6 \
              | int(self._bit5) << 5 \
              | int(self._bit4) << 4 \
              | int(self._used_before) << 1
          return flags
docs: Return a byte representation of ControlFlags.