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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 list_node(self, tab_level=-1):
 """ Lists the current Node and its children. Usage:: |----'MyNodeA' |----'MyNodeB' |----'MyNodeC' :param tab_level: Tab level. :type tab_level: int :return: Node listing. :rtype: unicode """


        output = ""
        tab_level += 1
        for i in range(tab_level):
            output += "\t"
        output += "|----'{0}'\n".format(self.name)
        for child in self.__children:
            output += child.list_node(tab_level)
        tab_level -= 1
        return output