refactor(FeedParser): (#3928)

lib/FeedExpander.php

@@ -32,6 +32,7 @@ abstract class FeedExpander extends BridgeAbstract
         $feedParser = new FeedParser();
         $this->feed = $feedParser->parseFeed($xmlString);
         $items = array_slice($this->feed['items'], 0, $maxItems);
+        // todo: extract parse logic out from FeedParser
         foreach ($items as $item) {
             // Give bridges a chance to modify the item
             $item = $this->parseItem($item);