Check in codegen test expectations.

test/codegen/expect/language/cast2_test_01_multi.js

+dart_library.library('language/cast2_test_01_multi', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__cast2_test_01_multi(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const cast2_test_01_multi = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  cast2_test_01_multi.C = class C extends core.Object {
+    new() {
+      this.foo = 42;
+      this.val = 0;
+    }
+    inc() {
+      this.val = dart.notNull(this.val) + 1;
+    }
+  };
+  dart.setSignature(cast2_test_01_multi.C, {
+    methods: () => ({inc: dart.definiteFunctionType(dart.void, [])})
+  });
+  cast2_test_01_multi.D = class D extends cast2_test_01_multi.C {
+    new() {
+      this.bar = 37;
+      super.new();
+    }
+  };
+  cast2_test_01_multi.main = function() {
+    let oc = new cast2_test_01_multi.C();
+    let od = new cast2_test_01_multi.D();
+    dart.dload(oc, 'bar');
+    oc.inc();
+    expect$.Expect.equals(1, oc.val);
+    oc.inc();
+    expect$.Expect.equals(2, oc.val);
+  };
+  dart.fn(cast2_test_01_multi.main, VoidTodynamic());
+  // Exports:
+  exports.cast2_test_01_multi = cast2_test_01_multi;
+});