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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 expand_all(self):
 """Expand all items."""


        def aux(item):
            self.item(item, open=True)
            children = self.get_children(item)
            for c in children:
                aux(c)

        children = self.get_children("")
        for c in children:
            aux(c)