[API](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-master-dev:ui/ui-test/src/main/java/androidx/ui/test/StateRestorationTester.kt?q=StateRestorationTester&ss=androidx), [sample](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-master-dev:ui/ui-foundation/src/androidTest/java/androidx/ui/foundation/ScrollerTest.kt;l=522;drc=9fb6924c83ba7af7cd95e45fbfb1f81863e5cf8a)
