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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def on(self):
 """Send an ON message to device group."""

        on_command = ExtendedSend(self._address,
                                  COMMAND_LIGHT_ON_0X11_NONE,
                                  self._udata,
                                  cmd2=0xff)
        on_command.set_checksum()
        self._send_method(on_command, self._on_message_received)