Use words please.

runtime/observatory/tests/service/string_escaping_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 // VMOptions=--compile-all --error_on_bad_type --error_on_bad_override
 
 library string_escaping_test;
 
 import 'package:observatory/service_io.dart';
 import 'package:unittest/unittest.dart';
 import 'test_helper.dart';
@@ skipping 33 matching lines @@
   longStringOdd = ".";
   for (int i = 0; i < 512; i++) longStringOdd += "𝄞";
 
   malformedWithLeadSurrogate = "before" + "𝄞"[0] + "after";
   malformedWithTrailSurrogate = "before" + "𝄞"[1] + "after";
 }
 
 var tests = [
 
 (Isolate isolate) =>
-  isolate.rootLib.load().then((Library lib) {
+  isolate.rootLibrary.load().then((Library lib) {
     expectFullString(String varName, String varValueAsString) {
       Field field = lib.variables.singleWhere((v) => v.name == varName);
       Instance value = field.value;
       expect(value.valueAsString, equals(varValueAsString));
       expect(value.valueAsStringIsTruncated, isFalse);
     }
     expectTruncatedString(String varName, String varValueAsString) {
       Field field = lib.variables.singleWhere((v) => v.name == varName);
       Instance value = field.value;
       expect(varValueAsString, startsWith(value.valueAsString));
@@ skipping 13 matching lines @@
     expectFullString('nullInTheMiddle', nullInTheMiddle);
     expectTruncatedString('longStringEven', longStringEven);
     expectTruncatedString('longStringOdd', longStringOdd);
     expectFullString('malformedWithLeadSurrogate', malformedWithLeadSurrogate);
     expectFullString('malformedWithTrailSurrogate', malformedWithTrailSurrogate);
   }),
 
 ];
 
 main(args) => runIsolateTests(args, tests, testeeBefore: script);