public static CoursesCounter Initialize(string id)
 {
     return(new CoursesCounter(new CoursesCounterId(id), CoursesCounterTotal.Initialize(), new List <CourseId>()));
 }
 public CoursesCounter(CoursesCounterId id, CoursesCounterTotal total, List <CourseId> existingCourses)
 {
     Id              = id;
     Total           = total;
     ExistingCourses = existingCourses;
 }