simulate issue #309

Example-Swift/PhotoBox.swift

@@ -23,6 +23,11 @@ final class NYTPhotoBox: NSObject, NYTPhoto {
     var image: UIImage?
     var imageData: Data?
     var placeholderImage: UIImage?
+    {
+        get {
+            return UIImage(named:"placeholder")
+        }
+    }
 
     var isPhoto: Bool {
         return value.itemType == .image

Example-Swift/PhotoViewerCoordinator.swift

@@ -28,7 +28,8 @@ final class PhotoViewerCoordinator: NSObject, NYTPhotoViewerDataSource {
         for box in slideshow {
             if box.isPhoto {
                 provider.fetchPhoto(named: box.value.name, then: { [weak self] (result) in
-                    box.image = result
+                    // simulate issue #309
+                    // box.image = result
                     self?.photoViewer.update(box)
                 })
             }

Example/Assets.xcassets/Contents.json

@@ -1,6 +1,6 @@
 {
   "info" : {
-    "version" : 1,
-    "author" : "xcode"
+    "author" : "xcode",
+    "version" : 1
   }
-}
+}

Example/Assets.xcassets/placeholder.imageset/Contents.json

@@ -0,0 +1,21 @@
+{
+  "images" : [
+    {
+      "filename" : "placeholder.png",
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}