InternalCoroutinesApi
@Target(allowedTargets = [AnnotationTarget.CLASS, AnnotationTarget.FUNCTION, AnnotationTarget.TYPEALIAS, AnnotationTarget.PROPERTY] )
Marks declarations that are internal in coroutines API, which means that should not be used outside of kotlinx.coroutines, because their signatures and semantics will change between future releases without any warnings and without providing any migration aids.