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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 add_subparser(subparsers):
 """Add command line option for exporting version information. """

    parser = subparsers.add_parser("version",
                                   help="Export versions of used software to stdout or a file ")
    parser.add_argument("--workdir", help="Directory export programs to in workdir/provenance/programs.txt",
                        default=None)