Bump to v4.0.0.

forIn.js

@@ -0,0 +1,34 @@
+define(['./internal/baseFor', './keysIn', './internal/toFunction'], function(baseFor, keysIn, toFunction) {
+
+  /**
+   * Iterates over own and inherited enumerable properties of an object invoking
+   * `iteratee` for each property. The iteratee is invoked with three arguments:
+   * (value, key, object). Iteratee functions may exit iteration early by explicitly
+   * returning `false`.
+   *
+   * @static
+   * @memberOf _
+   * @category Object
+   * @param {Object} object The object to iterate over.
+   * @param {Function} [iteratee=_.identity] The function invoked per iteration.
+   * @returns {Object} Returns `object`.
+   * @example
+   *
+   * function Foo() {
+   *   this.a = 1;
+   *   this.b = 2;
+   * }
+   *
+   * Foo.prototype.c = 3;
+   *
+   * _.forIn(new Foo, function(value, key) {
+   *   console.log(key);
+   * });
+   * // => logs 'a', 'b', then 'c' (iteration order is not guaranteed)
+   */
+  function forIn(object, iteratee) {
+    return object == null ? object : baseFor(object, toFunction(iteratee), keysIn);
+  }
+
+  return forIn;
+});