code: def unlock_key(self, data):
          
          if data.startswith(b'h:'):
              new = binascii.unhexlify(data[2:])
          else:
              new = data
          if len(new) == 6:
              self.unlock_code = new
              if not self.access_code:
                  # Don't reset the access code when programming, unless that seems
                  # to be the intent of the calling program.
                  self.access_code = new
          else:
              raise yubico_exception.InputError('Unlock key must be exactly 6 bytes')
docs: Access code to allow re-programming of your YubiKey.
  
          Supply data as either a raw bytestring, or a hexlified bytestring prefixed by 'h:'.
          The result, after any hex decoding, must be 6 bytes.