comefrom: <awangdev>Expression Add Operators_1.java
code: private void backtrack(List<String> list) {
  
          list.remove(list.size() - 1);
          list.remove(list.size() - 1);
      }
masked: private void var_0 ( List < String > var_1 ) {
    var_1 . remove ( var_1 . size ( ) - 1 ) ;
    var_1 . remove ( var_1 . size ( ) - 1 ) ;
  }
  