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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 set_extana_callback(self, callback, data=None):
 """Register a callback for incoming data packets from the SK8-ExtAna board. This method allows you to pass in a callable which will be called on receipt of each packet sent from the SK8-ExtAna board. Set to `None` to disable it again. Args: callback: a callable with the following signature: (ana1, ana2, temp, seq, timestamp, data) where: ana1, ana2 = current values of the two analogue inputs temp = temperature sensor reading seq = packet sequence number (int, 0-255) timestamp = value of time.time() when packet received data = value of `data` parameter passed to this method data: an optional arbitrary object that will be passed as a parameter to the callback """

        self.extana_callback = callback
        self.extana_callback_data = data