Clean up the oopsie. Rebuild the blank exercises.

node_modules/lodash/invert.js

@@ -2,6 +2,16 @@ var constant = require('./constant'),
     createInverter = require('./_createInverter'),
     identity = require('./identity');
 
+/** Used for built-in method references. */
+var objectProto = Object.prototype;
+
+/**
+ * Used to resolve the
+ * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
+ * of values.
+ */
+var nativeObjectToString = objectProto.toString;
+
 /**
  * Creates an object composed of the inverted keys and values of `object`.
  * If `object` contains duplicate values, subsequent values overwrite
@@ -21,6 +31,11 @@ var constant = require('./constant'),
  * // => { '1': 'c', '2': 'b' }
  */
 var invert = createInverter(function(result, value, key) {
+  if (value != null &&
+      typeof value.toString != 'function') {
+    value = nativeObjectToString.call(value);
+  }
+
   result[value] = key;
 }, constant(identity));