noModifierKeys = function (mapBrowserEvent) {
  const originalEvent = /** @type {KeyboardEvent|MouseEvent|TouchEvent} */ (
    mapBrowserEvent.originalEvent
  );
  return (
    !originalEvent.altKey &&
    !(originalEvent.metaKey || originalEvent.ctrlKey) &&
    !originalEvent.shiftKey
  );
}
Return `true` if no modifier key (alt-, shift- or platform-modifier-key) is
pressed.

@param {import("../MapBrowserEvent.js").default} mapBrowserEvent Map browser event.
@return {boolean} True only if there no modifier keys are pressed.
@api