docs: def InternalInit(self):
      """Initializes the device and obtains channel id."""
      self.cid = UsbHidTransport.U2FHID_BROADCAST_CID
      nonce = bytearray(os.urandom(8))
      r = self.InternalExchange(UsbHidTransport.U2FHID_INIT, nonce)
      if len(r) < 17:
        raise errors.HidError('unexpected init reply len')
      if r[0:8] != nonce:
        raise errors.HidError('nonce mismatch')
      self.cid = bytearray(r[8:12])
  
      self.u2fhid_version = r[12]