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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 _get_config_file_path(xdg_config_dir, xdg_config_file):
 """Search ``XDG_CONFIG_DIRS`` for a config file and return the first found. Search each of the standard XDG configuration directories for a configuration file. Return as soon as a configuration file is found. Beware that by the time client code attempts to open the file, it may be gone or otherwise inaccessible. :param xdg_config_dir: A string. The name of the directory that is suffixed to the end of each of the ``XDG_CONFIG_DIRS`` paths. :param xdg_config_file: A string. The name of the configuration file that is being searched for. :returns: A ``str`` path to a configuration file. :raises nailgun.config.ConfigFileError: When no configuration file can be found. """

    for config_dir in BaseDirectory.load_config_paths(xdg_config_dir):
        path = join(config_dir, xdg_config_file)
        if isfile(path):
            return path
    raise ConfigFileError(
        'No configuration files could be located after searching for a file '
        'named "{0}" in the standard XDG configuration paths, such as '
        '"~/.config/{1}/".'.format(xdg_config_file, xdg_config_dir)
    )