Grabbed dndbeyond's source code

```
~/go/bin/sourcemapper -output ddb -jsurl https://media.dndbeyond.com/character-app/static/js/main.90aa78c5.js
```

ddb_main/node_modules/@mui/utils/ownerWindow/ownerWindow.js

@@ -0,0 +1,5 @@
+import ownerDocument from '../ownerDocument';
+export default function ownerWindow(node) {
+  const doc = ownerDocument(node);
+  return doc.defaultView || window;
+}