Taking this into account:
   - currentPos === doc_id
   - the condition above ( ```doc._id.equals(prerollEndId)``` ) is true

then we are surely NOT past the target. This means that we don't need to evaluate this condition in this case. This could be an ```else if``` to the previous ```if```.

In fact, we don't really need to create a ```currentPos``` variable just for this and the condition could be
```
} else if (pastTarget(prerollEndId, doc._id)) {
   ...
}
```