npm and error messages

node_modules/csso/lib/utils/clone.js

@@ -0,0 +1,23 @@
+var List = require('./list');
+
+module.exports = function clone(node) {
+    var result = {};
+
+    for (var key in node) {
+        var value = node[key];
+
+        if (value) {
+            if (Array.isArray(value)) {
+                value = value.slice(0);
+            } else if (value instanceof List) {
+                value = new List(value.map(clone));
+            } else if (value.constructor === Object) {
+                value = clone(value);
+            }
+        }
+
+        result[key] = value;
+    }
+
+    return result;
+};