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/@emotion/weak-memoize/dist/emotion-weak-memoize.esm.js

@@ -0,0 +1,16 @@
+var weakMemoize = function weakMemoize(func) {
+  // $FlowFixMe flow doesn't include all non-primitive types as allowed for weakmaps
+  var cache = new WeakMap();
+  return function (arg) {
+    if (cache.has(arg)) {
+      // $FlowFixMe
+      return cache.get(arg);
+    }
+
+    var ret = func(arg);
+    cache.set(arg, ret);
+    return ret;
+  };
+};
+
+export { weakMemoize as default };