private static Level GetLevelElement(AbstractNum abstractNum, int levelIndex)
{
var oxmlLevel = abstractNum.Elements <Level>().FirstOrDefault(lv =>
{
return(lv.LevelIndex.Value == levelIndex);
});
if (oxmlLevel == null)
{
throw new OpenXmlPackageException(string.Format("Couldn't find the Level element by the level index (LevelIndex:{0})", levelIndex));
}
return(oxmlLevel);
}