Check in codegen test expectations.

test/codegen/expect/language/proxy2_test_03_multi.js

+dart_library.library('language/proxy2_test_03_multi', null, /* Imports */[
+  'dart_sdk'
+], function load__proxy2_test_03_multi(exports, dart_sdk) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const proxy2_test_03_multi = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  proxy2_test_03_multi.Fake = class Fake extends core.Object {
+    new() {
+    }
+  };
+  dart.setSignature(proxy2_test_03_multi.Fake, {
+    constructors: () => ({new: dart.definiteFunctionType(proxy2_test_03_multi.Fake, [])})
+  });
+  proxy2_test_03_multi.proxy = dart.const(new proxy2_test_03_multi.Fake());
+  proxy2_test_03_multi.WrongProxy = class WrongProxy extends core.Object {};
+  proxy2_test_03_multi.PrefixProxy = class PrefixProxy extends core.Object {};
+  proxy2_test_03_multi.main = function() {
+    try {
+      dart.dload(new proxy2_test_03_multi.PrefixProxy(), 'foo');
+    } catch (e) {
+    }
+
+  };
+  dart.fn(proxy2_test_03_multi.main, VoidTodynamic());
+  // Exports:
+  exports.proxy2_test_03_multi = proxy2_test_03_multi;
+});