ObservableListWrapper can not access outside ?

[CMingTseng]

Dear Sir i get

Cannot access 'com.lightningkite.kotlin.observable.list.ObservableList' which is a supertype of 'com.lightningkite.kotlin.observable.list.ObservableListWrapper'. Check your module classpath for missing or conflicting dependencies

i want use kotlin-observable at Android RecyclerView.Adapter to notify data change

https://android.googlesource.com/platform/frameworks/data-binding/+/c9a5d6f140f732ca0ff279a4b1ee315072e1c422/library/src/main/java/android/databinding/ObservableArrayList.java

THX