Grabbed dndbeyond's source code

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

ddb_main/packages/gfs/lib/index.js

@@ -0,0 +1,11 @@
+import { FeaturePreprocessor } from './FeaturePreprocessor';
+import { initProgram } from './LoopResolutionCalculator';
+export * from './types';
+export function generateCharacterState(_a) {
+    var rootFeatureIds = _a.rootFeatureIds, featureMap = _a.featureMap;
+    var derivedStatements = new FeaturePreprocessor().process({ rootFeatureIds: rootFeatureIds, featureMap: featureMap });
+    var state = initProgram({
+        expressions: derivedStatements,
+    });
+    return state;
+}