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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 on_ok(self):
 """ Perform restoration on the backup file selected """

        if self.dir_select.value:
            npyscreen.notify_wait('In the process of restoring',
                                  title='Restoring...')
            status = self.restore(self.dirs[self.dir_select.value[0]])
            if status[0]:
                npyscreen.notify_confirm('Status of restore:\n' +
                                         status[1])
            else:
                npyscreen.notify_confirm(status[1])
            self.quit()
        else:
            npyscreen.notify_confirm('Choose a version to restore from')