Why does ignoreIfFocusOn type expects a boolean only

[Shockwave3301]

The comment and the documentation states that I can pass a selector to it. But actual types don't allow it.
Even the "input" value from the example won't work.

   /**
     * Ignore scans if the currently focused element matches this selector. For
     * example, if you set this option to ``'input'``, scan events will not be
     * fired if an input field is focused. You can either pass an DOMElement, a
     * CSS selector or an array containing multiple besaid objects
     */

    ignoreIfFocusOn?: boolean;