question: private static void replaceTupleVariables ( HashMap < String , String > varChanges , TupleExpr tuple , Map < String , Value > valMap ) throws Exception { TupleVarRenamer visitor = new TupleVarRenamer ( varChanges , valMap ) ; tuple . visit ( visitor ) ; }
target:  Given a HashMap containing variable substitutions and a tuple, this method uses a visitor to iterate through the tuple and make the necessary substitutions