Check in codegen test expectations.

test/codegen/expect/language/null_method_test.js

Index: test/codegen/expect/language/null_method_test.js
diff --git a/test/codegen/expect/language/null_method_test.js b/test/codegen/expect/language/null_method_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..676bd658a188eac2c1761cd95507b4b2756865c3
--- /dev/null
+++ b/test/codegen/expect/language/null_method_test.js
@@ -0,0 +1,28 @@
+dart_library.library('language/null_method_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__null_method_test(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 null_method_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  null_method_test.C = class C extends core.Object {
+    foo(s) {
+      return dart.hashCode(s);
+    }
+  };
+  dart.setSignature(null_method_test.C, {
+    methods: () => ({foo: dart.definiteFunctionType(dart.dynamic, [dart.dynamic])})
+  });
+  null_method_test.main = function() {
+    let c = new null_method_test.C();
+    expect$.Expect.isNotNull(c.foo('foo'));
+    expect$.Expect.isNotNull(c.foo(null));
+  };
+  dart.fn(null_method_test.main, VoidTodynamic());
+  // Exports:
+  exports.null_method_test = null_method_test;
+});