Find in currently selected Zotero collection the items with all-upercase title

zotero-find-allupercase-title.js

var collection = ZoteroPane.getSelectedCollection();
var items = collection.getChildItems();
var returnItems = [];
for (let item of items) {
   let title = item.getField("title");
   if (title.toUpperCase() == title) {
      returnItems.push(title);
   }
}
return returnItems;