public async Task <IEnumerable <TutorResource> > GetAllByCourseIdAsync(int courseId)
        {
            var tutors = await _tutorService.ListByCourseIdAsync(courseId);

            var resources = _mapper
                            .Map <IEnumerable <Tutor>, IEnumerable <TutorResource> >(tutors);

            return(resources);
        }