public void UnlinkFromDescendant(TaskViewModel descendant)
 {
     this.SimulationDataChanged?.Invoke(this, EventArgs.Empty);
     this._task.UnlinkFromDescendant(descendant._task);
     this.JournalDataChanged?.Invoke(this, EventArgs.Empty);
 }
 public void UnlinkFromAncestor(TaskViewModel ancestor)
 {
     this.SimulationDataChanged?.Invoke(this, EventArgs.Empty);
     this._task.UnlinkFromAncestor(ancestor._task);
     this.JournalDataChanged?.Invoke(this, EventArgs.Empty);
 }