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/material/styles/useTheme.js

@@ -0,0 +1,14 @@
+'use client';
+
+import * as React from 'react';
+import { useTheme as useThemeSystem } from '@mui/system';
+import defaultTheme from './defaultTheme';
+import THEME_ID from './identifier';
+export default function useTheme() {
+  const theme = useThemeSystem(defaultTheme);
+  if (process.env.NODE_ENV !== 'production') {
+    // eslint-disable-next-line react-hooks/rules-of-hooks
+    React.useDebugValue(theme);
+  }
+  return theme[THEME_ID] || theme;
+}