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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 next_theme(self):
 """ Cycle to preview the next theme from the internal list of themes. """

        theme = self.term.theme_list.next(self.term.theme)
        while not self.term.check_theme(theme):
            theme = self.term.theme_list.next(theme)

        self.term.set_theme(theme)
        self.draw()
        message = self.term.theme.display_string
        self.term.show_notification(message, timeout=1)