Google Publisher Tag, how to remove event listener from Service

Question

There seem to be several questions on how to register events to a gpt service:
Google Publisher Tag registering to Events
registering to events with google publisher tag

How to do this is clearly defined in the documentation:
googletag.pubads().addEventListener('eventName', callbackFn);

I add my event to the service when the component (React) mounts inside the callback function of window.googletag.cmd.push as described in this tutorial by Google.

Now the problem is that every time I change page, more event listeners are added to the service. I can make sure only one event listener executes on the actually existing slots by using this method (from the documentation):

googletag.pubads().addEventListener('impressionViewable', function(event) {
  if (event.slot == targetSlot) { // will only run on target slot
    // Slot specific logic.
  }
});

But more an more event listeners will remain active and keep on executing (without executing the code within the if-statement).

Now, I assumed google would have implemented something like this (to run on componentWillUnmount):
googletag.pubads().removeEventListener('eventName', callbackFn);

But it doesn't exist in the documentation and I can't seem to find any way to remove active event listeners from the service?

Answer 1

So I went with this:

let eventListnerCreated = false;
if(!eventListnerCreated) {
    eventListnerCreated = googletag.pubads().addEventListener("slotRenderEnded", function(event) {
          // blablabla
    });
}

Not clean. But will work.

I know this doesn't solve the original issue of removing the event listener, but this will let's not create event listeners again and again.