Update Swift collection view interop example (#1837)

* Update uicollectionviewinterop.md
TextureGroup · May 26, 2020 · f0c0fae · f0c0fae
1 parent 74fd8f3
commit f0c0fae
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/docs/_docs/uicollectionviewinterop.md b/docs/_docs/uicollectionviewinterop.md
@@ -71,7 +71,14 @@ For this example, the data source method `collectionNode:nodeBlockForItemAtIndex
   </pre>
 
   <pre lang="swift" class = "swiftCode hidden">
-  // Click the "Edit on GitHub" button at the bottom of this 
+  // Setting the return type to implicitly unwrapped optional
+  // helps overcome compiler error when trying to return nil
+  func collectionNode(_ collectionNode: ASCollectionNode,
+                        nodeBlockForItemAt indexPath: IndexPath) -> ASCellNodeBlock! {
+        return optionalNode
+    }
+
+  // Click the "Edit on GitHub" button at the bottom of this  
   // page to contribute the swift code for this section. Thanks!
   </pre>
 </div>