public DietPlanPeriod(DietPlan dietPlan, DateTime startDate, DateTime endDate)
        {
            Guard.Against.Null(dietPlan, nameof(dietPlan));
            Guard.Against.Null(startDate, nameof(startDate));
            Guard.Against.Null(endDate, nameof(endDate));

            DietPlan  = dietPlan;
            StartDate = startDate;
            EndDate   = endDate;
        }
        public void EditDietPlan(DietPlan dietPlan)
        {
            Guard.Against.Null(dietPlan, nameof(dietPlan));

            DietPlan = dietPlan;
        }