Android studio 找不到符号方法setAdListener

当我试图更新Facebook SDK tp 6.2时，我遇到了这个错误

Interstituralad.setAdListener（新InterstituralListener（）{ ^ 符号：方法setAdListener（） 位置：Interstitalad类型的可变Interstitalad 我怎样才能解决这个问题

    public static void show_interstitialAd(Context context){
    if(interstitialAd.isAdLoaded()) {
        interstitialAd.show();
        interstitialAd.setAdListener(new InterstitialAdListener() {
            @Override
            public void onInterstitialDisplayed(Ad ad) {
                // Interstitial ad displayed callback
            }

            @Override
            public void onInterstitialDismissed(Ad ad) {
                // Interstitial dismissed callback
                interstitialAd.loadAd();
            }

            @Override
            public void onError(Ad ad, AdError adError) {
                // Ad error callback
                interstitialAd.loadAd();
            }

            @Override
            public void onAdLoaded(Ad ad) {
                // Show the ad
            }

            @Override
            public void onAdClicked(Ad ad) {
                // Ad clicked callback
            }

            @Override
            public void onLoggingImpression(Ad ad) {
                // Ad impression logged callback
            }
        });