I am trying to follow the example here to perform an offline verification (https://github.com/googlesamples/android-play-safetynet/blob/master/server/java/src/main/java/OfflineVerify.java). However, when I tried to import the following classes, Android Studio indicated unresolved references
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.json.webtoken.JsonWebSignature;
import org.apache.http.conn.ssl.DefaultHostnameVerifier;
The unresolved references were api and DefaultHostnameVerifier.
Am I missing some settings?