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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 _ensure_config_file_exists():
 """ Makes sure the config file exists. :raises: :class:`epab.core.new_config.exc.ConfigFileNotFoundError` """

    config_file = Path(ELIBConfig.config_file_path).absolute()
    if not config_file.exists():
        raise ConfigFileNotFoundError(ELIBConfig.config_file_path)