Blazor - Gantt - Show Tasks if ParentID Doesn't Exist / Isn't Loaded Declined - Not Valid

Hi,

I would like to be able to have an option to show tasks if the parentId does not exist or is not loaded.  At present, if a task has a parentId that doesn't exist i the data collection, the task will not be shown.

I am implementing task filtering logic in the base collection and am having to do work to test if a parent Id exists before rendering.

@page "/gantt1"
@using Syncfusion.Blazor.Gantt
Gantt Chart
    @*ProjectStartDate="@ProjectStart" ProjectEndDate="@ProjectEnd"*@
    
@code{
    public SfGantt gantt { get; set; }

    public DateTime ProjectStart = new DateTime(2019, 4, 1);
    public DateTime ProjectEnd = new DateTime(2019, 5, 4);
    public DateTime EventDay1 = new DateTime(2019, 4, 17);
    public DateTime HolidayFrom1 = new DateTime(2019, 4, 11);
    public DateTime HolidayTo1 = new DateTime(2019, 4, 12);
    public DateTime HolidayFrom2 = new DateTime(2019, 4, 1);
    public DateTime HolidayTo2 = new DateTime(2019, 4, 1);
    public List TaskCollection { get; set; }
    public int DefaultUnitWidth = 33;
    public int TopTierCount = 1;
    public int BottomTierCount = 1;
    TimelineViewMode TopTierUnit = TimelineViewMode.Week;
    TimelineViewMode BottomTierUnit = TimelineViewMode.Day;
    string TopTierFormat = "MMM dd, yyyy";
    string BottomTierFormat = "";
    public string[] Searchfields = new string[] { "TaskId", "TaskName", "StartDate", "EndDate", "Duration", "Progress", "Predecessor" };
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }
    
    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public int Work { get; set; }
        public string Predecessor { get; set; }
        public int? ParentID { get; set; }
    }
    public static List GetTaskCollection()
    {
        List Tasks = new List() {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation Id=1",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            ParentID = null
            },
        new TaskData() {
            TaskId = 2,
            TaskName = "Project initiation Id=2",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            ParentID = 1
        },
        new TaskData() {
            TaskId = 3,
            TaskName = "Project initiation Id=3 - TASK WILL NOT BE SHOWN",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            ParentID = 4
        }
    };
        return Tasks;
    }
}