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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 _open_repo(args, path_key='<path>'):
 """Open and return the repository containing the specified file. The file is specified by looking up `path_key` in `args`. This value or `None` is passed to `open_repository`. Returns: A `Repository` instance. Raises: ExitError: If there is a problem opening the repo. """

    path = pathlib.Path(args[path_key]) if args[path_key] else None

    try:
        repo = open_repository(path)
    except ValueError as exc:
        raise ExitError(ExitCode.DATA_ERR, str(exc))

    return repo