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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 usage(self, subcommand):

 """
 Return a brief description of how to use this command, by
 default from the attribute ``self.help``.
 
 """

        if len(self.option_list) > 0:
            usage = '%%prog %s [options] %s' % (subcommand, self.args)
        else:
            usage = '%%prog %s %s' % (subcommand, self.args)
        if self.help:
            return '%s\n\n%s' % (usage, self.help)
        else:
            return usage