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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 add_group(self, number, name, led_type):
 """ Add a group. :param number: Group number (1-4). :param name: Group name. :param led_type: Either `RGBW`, `WRGB`, `RGBWW`, `WHITE`, `DIMMER` or `BRIDGE_LED`. :returns: Added group. """

        group = group_factory(self, number, name, led_type)
        self.groups.append(group)
        return group