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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 rename_selected_state(self, key_value, modifier_mask):
 """Callback method for shortcut action rename Searches for a single selected state model and open the according page. Page is created if it is not existing. Then the rename method of the state controller is called. :param key_value: :param modifier_mask: """

        selection = self.current_state_machine_m.selection
        if len(selection.states) == 1 and len(selection) == 1:
            selected_state = selection.get_selected_state()
            self.activate_state_tab(selected_state)
            _, state_identifier = self.find_page_of_state_m(selected_state)
            state_controller = self.tabs[state_identifier]['controller']
            state_controller.rename()