public IActionResult Get(int id)
        {
            Instructor instructor = _instructorRepository.Get(id);

            if (instructor == null)
            {
                return(BadRequest());
            }
            return(Ok(instructor));
        }
        public InstructorViewModel Create(Instructor entity)
        {
            _instructorRepository.Add(entity);
            var instructor = _instructorRepository
                             .Get <Course>(
                i => i.Name.Equals(entity.Name, StringComparison.OrdinalIgnoreCase)
                );

            return(new InstructorViewModel()
            {
                Id = instructor.Id,
                Name = instructor.Name,
                Designation = instructor.Designation,
                Skill = instructor.Skill
            });
        }