static IEnumerable<course> createCourses(ProductsDefine.productDescrLow prod, List<string> modules = null, List<string> lessons = null) { var cnt = 0; foreach (var pd in prod.productParts()) { yield return new course() { lessons = createLessons(pd.getLessons()), jsonId = (cnt++).ToString(), title = pd.title, level = pd.partLevelName(), testFileName = pd.testFileName(), //LMLevel = pd.partIdx / 2, }; } }