private async void ViewLeaves()
        {
            try
            {
                //Todo----Optimize below code to run in lesser time.
                //todo----add suitable catch statement for this try.
                IsBusy    = true;
                IsVisible = false;
                ActivityIndicatorTitle = "Please wait while data is being loaded.";

                ListItems = new ObservableCollection <CalendarItem>();

                var x = await FirebaseService.GetAll(_month, _year);

                foreach (var item in x)
                {
                    ListItems.Add(item);
                }
            }
            finally
            {
                IsBusy = false;
                Title  = string.Join("\t", Title, string.Concat("(", _month, ' ', _year, ")"));
            }
        }