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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 enter_linking_mode(self, group=0x01):
 """Tell a device to enter All-Linking Mode. Same as holding down the Set button for 10 sec. Default group is 0x01. Not supported by i1 devices. """

        msg = ExtendedSend(self._address,
                           COMMAND_ENTER_LINKING_MODE_0X09_NONE,
                           cmd2=group,
                           userdata=Userdata())
        msg.set_checksum()
        self._send_msg(msg)