Re-Order the array keys so that JSON will be an array, not an object

lib/PayPal/Api/ItemList.php

@@ -27,7 +27,7 @@ class ItemList extends PayPalModel
      */
     public function setItems($items)
     {
-        $this->items = $items;
+        $this->items = array_values($items);
         return $this;
     }
 

tests/PayPal/Test/Api/ItemListTest.php

@@ -2,6 +2,7 @@
 
 namespace PayPal\Test\Api;
 
+use PayPal\Api\Item;
 use PayPal\Api\ItemList;
 use PHPUnit\Framework\TestCase;
 
@@ -18,7 +19,7 @@ class ItemListTest extends TestCase
      */
     public static function getJson()
     {
-        return '{"items":' . ItemTest::getJson() . ',"shipping_address":' . ShippingAddressTest::getJson() . ',"shipping_method":"TestSample","shipping_phone_number":"TestSample"}';
+        return '{"items":[' . ItemTest::getJson() . '],"shipping_address":' . ShippingAddressTest::getJson() . ',"shipping_method":"TestSample","shipping_phone_number":"TestSample"}';
     }
 
     /**
@@ -53,9 +54,28 @@ public function testSerializationDeserialization()
      */
     public function testGetters($obj)
     {
-        $this->assertEquals($obj->getItems(), ItemTest::getObject());
+        $this->assertEquals($obj->getItems(), array(ItemTest::getObject()));
         $this->assertEquals($obj->getShippingAddress(), ShippingAddressTest::getObject());
         $this->assertEquals($obj->getShippingMethod(), "TestSample");
         $this->assertEquals($obj->getShippingPhoneNumber(), "TestSample");
     }
+
+	/**
+     * @depends testSerializationDeserialization
+     * @param ItemList $obj
+     */
+    public function testAddRemove($obj)
+    {
+		$item2 = new Item(ItemTest::getJSON());
+		$item2->setSku('TestSample2');
+        $item3 = new Item(ItemTest::getJSON());
+		$item3->setSku('TestSample3');
+		$obj->addItem($item2);
+		$obj->addItem($item3);
+		$this->assertCount(3, $obj->getItems());
+		$obj->removeItem($item2);
+
+		$this->assertCount(2, $obj->getItems());
+		$this->assertContains('"items":[', $obj->toJSON());
+    }
 }