Android
> **Requires Opt-in** RequiresOptIn.Level.ERROR ```kotlin public annotation class ExperimentalFollowingSubspaceApi ``` Marks Subspace APIs that are experimental and likely to change or be removed in the future. Any usage of a declaration annotated with `@ExperimentalFollowingSubspaceApi` must be accepted either by annotating that usage with `@OptIn(ExperimentalFollowingSubspaceApi::class)` or by propagating the annotation to the containing declaration.