marked problems as EC

SunJieMing · SunJieMing · commit 590f2a405291 · 2017-10-02T08:02:39.000-07:00
diff --git a/src/objects.js b/src/objects.js
@@ -23,6 +23,8 @@ const pairs = (obj) => {
   // http://underscorejs.org/#pairs
 };
 
+/* Extra credit */
+
 const invert = (obj) => {
   // Returns a copy of the object where the keys have become the values and the values the keys.
   // Assume that all of the object's values will be unique and string serializable.
