How to set selection to empty

I want to set the selection to empty when the editor is blurred。How should selection be dispatched (I searched the official documents and discuss and found nothing related)

      extensions: [
          blur: (event: FocusEvent, view: EditorView) => {
              selection: // empty

The selection cannot be empty, it must always hold at least one cursor.

thenks, then I will think of other solutions to meet my needs