@@ -476,19 +476,22 @@ createMenu(menuConfig);
 **Good**:
 ```javascript
 var menuConfig = {
-title: null,
-body: 'Bar',
-buttonText: null,
+title: 'Order',
+// User did not include 'body' key
+buttonText: 'Send',
 cancellable: true
 }
 
 function createMenu(config) {
-Object.assign(config, {
+config = Object.assign({}, {
 title: 'Foo',
 body: 'Bar',
 buttonText: 'Baz',
 cancellable: true
-});
+}, config);
+
+// config now equals: {title: "Order", body: "Bar", buttonText: "Send", cancellable: true}
+// ...
 }
 
 createMenu(menuConfig);
@@ -1204,7 +1207,7 @@ class Square extends Shape {
 setLength(length) {
 this.length = length;
 }
-
+
 getArea() {
 return this.length * this.length;
 }