public async Task <IActionResult> UpdateDemand([FromBody] AppDemand demand)
        {
            if (ModelState.IsValid)
            {
                try
                {
                    await demandRepo.UpdateDemand(demand);

                    return(Ok());
                }
                catch (Exception excp)
                {
                    if (excp.GetType().FullName ==
                        "Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException")
                    {
                        return(NotFound());
                    }

                    return(BadRequest(excp));
                }
            }

            return(BadRequest());
        }