penOnly = function (mapBrowserEvent) {
  const pointerEvt = mapBrowserEvent.originalEvent;
  // see https://www.w3.org/TR/pointerevents/#widl-PointerEvent-pointerType
  return 'pointerId' in pointerEvt && pointerEvt.pointerType === 'pen';
}
Return `true` if the event originates from a digital pen.

@param {import("../MapBrowserEvent.js").default} mapBrowserEvent Map browser event.
@return {boolean} True if the event originates from a digital pen.
@api