public override void OnActionExecuting(HttpActionContext context)
{
ModuleRepository moduleRepository = new ModuleRepository(new MyRoomDbContext());
bool hasChildrens = moduleRepository.HasCategoriesChildrens((int)context.ActionArguments["key"]);
if (!hasChildrens)
throw new HttpResponseException(context.Request.CreateErrorResponse(HttpStatusCode.NotAcceptable, "Please, delete the categories children"));
}