public async virtual Task <IList <Assignment> > GetAssignmentsAsync()
        {
            //return await Assignments
            //    .AsNoTracking()
            //    .ToListAsync();
            var assignments = new List <Assignment>();

            foreach (var assignment in Assignments.AsNoTracking().ToList())
            {
                assignments.Add(await GetAssignmentById(assignment.Id));
            }

            return(assignments);
        }