public HttpResponseMessage GetCoursesByInstructor([FromBody] GetCoursesByInstructorRequest request) { var response = _service.FetchCoursesByInstructor(request); if (response.Instructor != null && response.Courses != null) { return(Request.CreateResponse <GetCoursesByInstructorResponse>(HttpStatusCode.OK, response)); } else if (response.Instructor != null && response.Courses == null) { return(Request.CreateErrorResponse(HttpStatusCode.NoContent, "This instructor has no courses")); } else { return(Request.CreateErrorResponse(HttpStatusCode.NotFound, "Something went wrong...")); } }