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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_child(self, child):
 """ Adds given child to the node. Usage:: True [<AbstractCompositeNode object at 0x10107afe0>] :param child: Child node. :type child: AbstractNode or AbstractCompositeNode or Object :return: Method success. :rtype: bool """


        self.__children.append(child)
        child.parent = self
        return True