public Fluent returns(Function<String, Void> checker) throws ParseException { final Ast.Program program = parseProgram(pig); final PigRelBuilder builder = PigRelBuilder.create(PigRelBuilderTest.config().build()); final StringWriter sw = new StringWriter(); new CalciteHandler(builder, sw).handle(program); checker.apply(Util.toLinux(sw.toString())); return this; }