update

node_modules/clean-css/lib/utils/override.js

@@ -0,0 +1,34 @@
+function override(source1, source2) {
+  var target = {};
+  var key1;
+  var key2;
+  var item;
+
+  for (key1 in source1) {
+    item = source1[key1];
+
+    if (Array.isArray(item)) {
+      target[key1] = item.slice(0);
+    } else if (typeof item == 'object' && item !== null) {
+      target[key1] = override(item, {});
+    } else {
+      target[key1] = item;
+    }
+  }
+
+  for (key2 in source2) {
+    item = source2[key2];
+
+    if (key2 in target && Array.isArray(item)) {
+      target[key2] = item.slice(0);
+    } else if (key2 in target && typeof item == 'object' && item !== null) {
+      target[key2] = override(target[key2], item);
+    } else {
+      target[key2] = item;
+    }
+  }
+
+  return target;
+}
+
+module.exports = override;