[ember] initializer and instanceInitializer are static methods

types/ember/index.d.ts

@@ -1075,14 +1075,14 @@ declare module 'ember' {
              * after all initializers and therefore after all code is loaded and the app is
              * ready.
              */
-            initializer(initializer: Initializer<Engine>): void;
+            static initializer(initializer: Initializer<Engine>): void;
             /**
              * Instance initializers run after all initializers have run. Because
              * instance initializers run after the app is fully set up. We have access
              * to the store, container, and other items. However, these initializers run
              * after code has loaded and are not allowed to defer readiness.
              */
-            instanceInitializer(instanceInitializer: Initializer<EngineInstance>): void;
+            static instanceInitializer(instanceInitializer: Initializer<EngineInstance>): void;
             /**
              * Set this to provide an alternate class to `Ember.DefaultResolver`
              */

types/ember/test/application.ts

@@ -1,27 +1,33 @@
 import Ember from 'ember';
 import { assertType } from "./lib/assert";
 
-let App = Ember.Application.create({
-    customEvents: {
-        paste: 'paste'
-    }
+let BaseApp = Ember.Application.extend({
+    modulePrefix: 'my-app'
 });
 
-App.initializer({
+BaseApp.initializer({
     name: 'my-initializer',
     initialize(app) {
         app.register('foo:bar', Ember.Object.extend({ foo: 'bar' }));
     }
 });
 
-App.instanceInitializer({
+BaseApp.instanceInitializer({
     name: 'my-instance-initializer',
     initialize(app) {
         app.lookup('foo:bar').get('foo');
     }
 });
 
-let App2 = Ember.Application.create({
+let App1 = BaseApp.create({
+    rootElement: '#app-one',
+    customEvents: {
+        paste: 'paste'
+    }
+});
+
+let App2 = BaseApp.create({
+    rootElement: '#app-two',
     customEvents: {
         mouseenter: null,
         mouseleave: null