public ActionResult <IEnumerable <CourseDto> > GetCourses(int authorId)
{
var author = _courseLibraryRepository.GetAuthor(authorId);
if (author == null)
{
return(NotFound());
}
var coursesFromRepo = _courseLibraryRepository.GetAllCourse(authorId);
return(Ok(_mapper.Map <IEnumerable <CourseDto> >(coursesFromRepo)));
}