public async Task <ActionResult <CustomResponse <ViewResponse> > > View(
            [FromRoute][BindRequired][ModelBinder(Name = "problemsetId")] Problemset problemset,
            [FromRoute] string id
            )
        {
            var entryId = await problemset.GetProblemEntryId(id);

            if (!entryId.HasValue)
            {
                ModelState.AddModelError("id", "The specified id does not exist in the problemset.");
                return(BadRequest(ModelState));
            }

            var content = await problemset.GetProblemContent(entryId.Value);

            return(new CustomResponse <ViewResponse>(new ViewResponse()
            {
                EntryId = entryId.Value,
                Content = content
            }));
        }