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