@staticmethod
def unpack_value(key, source_time, value):
    """
        Function that parses response from source and returns following tuple: (key, source_time, value)
        Key can then be used to find the right instance and update values.

        Can be overridden and adapted to the controller it is to be used in.

        :returns: tuple(key, source_time, value)
        :rtype: tuple

        Example::

            def parse_item(self, item):
                for parser in self.get_parsers():
                    if parser.can_unpack_value(item):
                        key, source_time, value = parser.unpack_value(item)
                        self.send_datachange(key, source_time, value)

        """
    return key, source_time, value
