Revert "Removed unused function"

This reverts commit 1821c00c.

shorthand.ml

@@ -273,3 +273,10 @@ let transform = function
   | v -> v
 
 let compress = Util.transform_stylesheet transform
+
+let transform_unfold = function
+  | Statement (Ruleset (selectors, decls)) ->
+    Statement (Ruleset (selectors, unfold decls))
+  | v -> v
+
+let unfold_stylesheet = Util.transform_stylesheet transform_unfold