admobadapter/src/main/java/com/clockbyte/admobadapter/AdmobFetcher.java
public synchronized NativeAd getAdForIndex(final int index) {
        NativeAd adNative = null;
        if(index >= 0)
            adNative = (NativeAd) adMapAtIndex.get(index);

        if (adNative == null && mPrefetchedAdList.size() > 0) {
            adNative = mPrefetchedAdList.remove(0);

            if (adNative != null) {
                adMapAtIndex.put(index, adNative);
            }
        }

        ensurePrefetchAmount(); // Make sure we have enough pre-fetched ads
        return adNative;
    }
public synchronized NativeAd getAdForIndex(final int index) {
        NativeAd adNative = null;
        if(index >= 0)
            adNative = (NativeAd) adMapAtIndex.get(index);

        if (adNative == null && mPrefetchedAdList.size() > 0) {
            adNative = mPrefetchedAdList.remove(0);

            if (adNative != null) {
                adMapAtIndex.put(index, adNative);
            }
        }

        ensurePrefetchAmount(); // Make sure we have enough pre-fetched ads
        return adNative;
    }
Gets native ad at a particular index in the fetched ads list.

@param index the index of ad in the fetched ads list
@return the native ad in the list
@see #getFetchedAdsCount()