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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 used_options(self):
 """Return options already used in the command line rtype: command.Option generator """

        for option_str in filter(lambda c: c.startswith('-'), self.words):
            for option in list(self.cmd.options.values()):
                if option_str in option.option_strings:
                    yield option