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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 corpus(self):
        '''Command to add a corpus to the dsrt library'''

        # Initialize the addcorpus subcommand's argparser
        description = '''The corpus subcommand has a number of subcommands of its own, including:
            list\t-\tlists all available corpora in dsrt's library
            add\t-\tadds a corpus to dsrt's library'''

        parser = argparse.ArgumentParser(description=description)
        self.init_corpus_args(parser)

        # parse the args we got
        args = parser.parse_args(sys.argv[2:3])

        corpus_command = 'corpus_' + args.corpus_command

        if not hasattr(self, corpus_command):
            print('Unrecognized corpus command.')
            parser.print_help()
            exit(1)

        getattr(self, corpus_command)()