public async Task UpdateTrainer(int id, CreateOrUpdateTrainerRequest request)
        {
            var emp = context.Employees.Find(request.EmployeeId).PositionId = 2;
            var pw  = await context.Trainers.FindAsync(id);

            pw.EmployeeId       = request.EmployeeId;
            pw.ProgramWorkoutId = request.ProgramWorkoutId != 0 ? request.ProgramWorkoutId : null;
            await context.SaveChangesAsync();
        }
        public async Task AddTrainer(CreateOrUpdateTrainerRequest request)
        {
            var tr = new Trainer {
                ProgramWorkoutId = request.ProgramWorkoutId,
                EmployeeId       = request.EmployeeId
            };
            await context.Trainers.AddAsync(tr);

            await context.SaveChangesAsync();
        }