def bytes(self):
        """Return a byte representation of the message flags."""
        flagByte = 0x00
        messageType = 0
        if self._messageType is not None:
            messageType = self._messageType << 5
        extendedBit = 0 if self._extended is None else self._extended << 4
        hopsMax = 0 if self._hopsMax is None else self._hopsMax
        hopsLeft = 0 if self._hopsLeft is None else (self._hopsLeft << 2)
        flagByte = flagByte | messageType | extendedBit | hopsLeft | hopsMax
        return bytes([flagByte])
Return a byte representation of the message flags.