I started working in the Android field and I worked in an app that uses geofencing, using the google documentation I found a class that I can not use " GeofencingClient " and I do not know which dependency requires, research on the Internet but I can not find it, attach a piece of code.
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
private GeofencingClient mGeofencingClient;
}