class TestAdapter<VH : RecyclerView.ViewHolder> : RecyclerView.Adapter<VH>() {
    override fun getItemCount(): Int {
        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
    }

    override fun onBindViewHolder(holder: VH, position: Int) {
        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
    }

    override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): VH {
        return TestHolder(null)
    }

    class TestHolder(view: View?) : RecyclerView.ViewHolder(view) {

    }
}