admobadapter/src/main/java/com/clockbyte/admobadapter/bannerads/BannerAdPresetCyclingList.java
@Override
    public boolean addAll(Collection<? extends BannerAdPreset> c) {
        ArrayList<BannerAdPreset> lst = new ArrayList<>();
        for (BannerAdPreset eap : c) {
            if(eap!=null && eap.isValid())
                lst.add(eap);
        }
        return super.addAll(lst);
    }
@Override
    public boolean addAll(Collection<? extends BannerAdPreset> c) {
        ArrayList<BannerAdPreset> lst = new ArrayList<>();
        for (BannerAdPreset eap : c) {
            if(eap!=null && eap.isValid())
                lst.add(eap);
        }
        return super.addAll(lst);
    }
Tries to add items to collection if valid {@link BannerAdPreset#isValid()}
@return true if items were added, false - otherwise