https://developers.google.com/android/reference/com/google/android/gms/cast/framework/IntroductoryOverlay
IntroductoryOverlay | Google Play services | Google for Developers
google play servicesdevelopers
https://developers.google.cn/android/reference/com/google/android/gms/cast/framework/IntroductoryOverlay.Builder?authuser=0
IntroductoryOverlay.Builder | Google Play services | Google for Developers
google play servicesbuilderdevelopers