Bump to v4.0.0.

defaults.js

@@ -0,0 +1,31 @@
+define(['./internal/apply', './internal/assignInDefaults', './assignInWith', './rest'], function(apply, assignInDefaults, assignInWith, rest) {
+
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
+  /**
+   * Assigns own and inherited enumerable properties of source objects to the
+   * destination object for all destination properties that resolve to `undefined`.
+   * Source objects are applied from left to right. Once a property is set,
+   * additional values of the same property are ignored.
+   *
+   * **Note:** This method mutates `object`.
+   *
+   * @static
+   * @memberOf _
+   * @category Object
+   * @param {Object} object The destination object.
+   * @param {...Object} [sources] The source objects.
+   * @returns {Object} Returns `object`.
+   * @example
+   *
+   * _.defaults({ 'user': 'barney' }, { 'age': 36 }, { 'user': 'fred' });
+   * // => { 'user': 'barney', 'age': 36 }
+   */
+  var defaults = rest(function(args) {
+    args.push(undefined, assignInDefaults);
+    return apply(assignInWith, undefined, args);
+  });
+
+  return defaults;
+});