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/styled-components/src/utils/interleave.js

@@ -0,0 +1,15 @@
+// @flow
+import type { Interpolation } from '../types';
+
+export default (
+  strings: Array<string>,
+  interpolations: Array<Interpolation>
+): Array<Interpolation> => {
+  const result = [strings[0]];
+
+  for (let i = 0, len = interpolations.length; i < len; i += 1) {
+    result.push(interpolations[i], strings[i + 1]);
+  }
+
+  return result;
+};