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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 load_user_config(args, log):
 """Load settings from the user's confiuration file, and add them to `args`. Settings are loaded from the configuration file in the user's home directory. Those parameters are added (as attributes) to the `args` object. Arguments --------- args : `argparse.Namespace` Namespace object to which configuration attributes will be added. Returns ------- args : `argparse.Namespace` Namespace object with added attributes. """

    if not os.path.exists(_CONFIG_PATH):
        err_str = (
            "Configuration file does not exists ({}).\n".format(_CONFIG_PATH) +
            "Run `python -m astrocats setup` to configure.")
        log_raise(log, err_str)

    config = json.load(open(_CONFIG_PATH, 'r'))
    setattr(args, _BASE_PATH_KEY, config[_BASE_PATH_KEY])
    log.debug("Loaded configuration: {}: {}".format(_BASE_PATH_KEY, config[
        _BASE_PATH_KEY]))
    return args