public void AddWorkTask(WorkingTimeRecordForReport workingTime)
        {
            var targetTask = _DailyWorkTaskUnits.FirstOrDefault(t => t.NeedToSummarize(workingTime));

            if (targetTask == null)
            {
                targetTask = new DailyWorkTaskUnit(workingTime);
                _DailyWorkTaskUnits.Add(targetTask);
            }

            targetTask.AddWorkingTime(workingTime.ConvertToWorkingTimeRange());
        }
        public async void EditWorkTaskTime(WorkingTimeRecordForReport record)
        {
            var editDialogVm = new WorkingTimeRangeEditDialogViewModel(record.ConvertToWorkingTimeRange());

            var view = new WorkingTimeRangeEditDialog
            {
                DataContext = editDialogVm
            };

            //show the dialog
            var result = (bool?)await DialogHost.Show(view);

            if (result.HasValue && result.Value)
            {
                var editObj = editDialogVm.WorkingTimeViewModel.DomainModel;
                _WorkTaskModel.EditWorkingTime(editObj);

                _Model.Load();
            }
        }