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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 show_graphs(self):
 """Show a pile of the graph selected for dislpay"""

        elements = itertools.chain.from_iterable(
            ([graph]
             for graph in self.visible_graphs.values()))
        self.graph_place_holder.original_widget = urwid.Pile(elements)