package Ġcom . quart ack . bd apter . sample . tree . model Ċ Ċ import Ġandroidx . annotation . Keep Ċ import Ġcom . quart ack . bd apter . annotation . Bd apter ViewHolder Ċ import Ġcom . quart ack . bd apter . sample . databinding . View holder Internal Item Binding Ċ import Ġcom . quart ack . bd apter . sample . tree . Tree ViewModel Ċ Ċ @ Keep Ċ @ Bd apter ViewHolder ( ĊĠĠĠ Ġdata Binding Ġ= ĠView holder Internal Item Binding :: class , ĊĠĠĠ ĠviewModel Class Ġ= ĠTree ViewModel :: class Ċ ) Ċ data Ġclass ĠInternal Item ( ĊĠĠĠ Ġval Ġid : ĠInt , ĊĠĠĠ Ġval Ġchild Items : ĠList < Leaf Item >, ĊĠĠĠ Ġvar ĠisOpen : ĠBoolean Ġ= Ġtrue Ċ ) Ċ