New Post: CheckListBox - How to uncheck all checked items

I cannot figure out how to clear all checked items in a CheckListBox
I have a long list in my checklistbox and using a button in the GUI I want to clear all checked items but I cannot figure out how to clear.

I would have thought that I could iterate over the Items property but the type of the items are only string.

Any input anyone ?

My xaml :

<xctk:CheckListBox
      Name="TaskStatusFilter_CheckListBox"
      ItemsSource="{Binding TaskStatuses}"
  SelectedItemsOverride="{Binding SelectedTaskStatuses}" 
  HorizontalAlignment="Left" Height="100" 
  Margin="0,0,0,-35" 
 VerticalAlignment="Top" Width="150"/>

Both TaskStatuses and SelectedTaskStatuses are ObservableCollection<String>